Influence Of Land Use Land Cover And Hydrology On The Spatial And Temporal Characteristics Of Dissolved Organic Matter Dom In Multiple Aquatic Ecosystems

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Influence of Land Use, Land Cover, and Hydrology on the Spatial and Temporal Characteristics of Dissolved Organic Matter (DOM) in Multiple Aquatic Ecosystems

Author : Shatrughan Singh
Publisher :
ISBN 13 :
Total Pages : 159 pages
Book Rating : 4.:/5 (1 download)

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Book Synopsis Influence of Land Use, Land Cover, and Hydrology on the Spatial and Temporal Characteristics of Dissolved Organic Matter (DOM) in Multiple Aquatic Ecosystems by : Shatrughan Singh

Download or read book Influence of Land Use, Land Cover, and Hydrology on the Spatial and Temporal Characteristics of Dissolved Organic Matter (DOM) in Multiple Aquatic Ecosystems written by Shatrughan Singh and published by . This book was released on 2017 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spatial and temporal patterns of dissolved organic matter (DOM) were characterized using a combination of spectro-fluorometric measurements and multivariate analysis techniques. The study was conducted over a four-year (2012-2016) period in multiple watersheds located in the Gulf-Atlantic Coastal Plain Physiographic region of the southeast USA as well as in the Indo-Gangetic Plain of India. Surface water samples were collected from five major lakes in the Mississippi, an estuarine region in the southeastern Louisiana, and from the coastal region in the eastern Mississippi Sound in the USA, and a large river (Ganges River) in India. Absorption and fluorescence measurements were performed to generate absorption spectra and excitation-emission matrices (EEMs). Using parallel factor analyses (PARAFAC), EEM models were developed to characterize the biogeochemistry of DOM in three studies in this project. Principal component analysis and regression analyses of DOM data indicated that the northern Mississippi lakes were majorly influenced by agricultural land use, estuarine region was affected by natural DOM export from forests and wetlands, while the coastal waters were affected by a mix of anthropogenic and natural inputs of DOM. Spatial analyses indicated that DOM derived from watershed with increased wetland coverage was humic and aromatic while the DOM derived from agricultural watersheds was bioavailable. Temporal patterns of DOM in the estuary indicated the influence of hydrologic conditions and summer temperatures, and revealed strong seasonality in DOM evolution in the watershed. During high discharge periods (spring), aromatic and humic DOM was exported from the watershed while strong photochemical degradation during summer resulted bioavailable DOM. Comparison between two river systems, a highly urbanized large river and a small pristine river, indicated the influence of anthropogenic inputs of DOM in the large river system. DOM was bioavailable during summer due to anthropogenic activities in the large river system while it varied with hydrological connectivity in a small river system during summer and winter. In conclusion, this study has improved my understandings of the DOM properties, which are critical for a comprehensive assessment of biogeochemical processes undergoing in important water bodies on which our society is heavily dependent upon.

Hydrologic and Land Cover Effects on Sources and Fate of In-Stream Fluorescent Dissolved Organic Matter

Author : Baek Soo P. Lee
Publisher :
ISBN 13 :
Total Pages : 147 pages
Book Rating : 4.:/5 (93 download)

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Book Synopsis Hydrologic and Land Cover Effects on Sources and Fate of In-Stream Fluorescent Dissolved Organic Matter by : Baek Soo P. Lee

Download or read book Hydrologic and Land Cover Effects on Sources and Fate of In-Stream Fluorescent Dissolved Organic Matter written by Baek Soo P. Lee and published by . This book was released on 2015 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissolved organic matter (DOM) is a critical component of the carbon cycle linking terrestrial and aquatic ecosystems. Although many factors influence DOM fluxes and quality in rivers, controls on DOM compositions in catchments of the western U.S. are poorly understood. UV and fluorescent spectroscopy is a simpler, faster, and less expensive DOM fingerprinting technique compared to techniques, such as nuclear magnetic resonance (NMR) spectroscopy or wet chemical fractionation, and could be useful for characterizing complex DOM chemistry. However, only 1 % of DOM is estimated to be fluorescent, and the utility of UV and fluorescent spectroscopy for DOM characterization needs to be further investigated. This dissertation applied UV and fluorescent spectroscopy to examine hydrologic and land cover controls on DOM chemistry in streams of 45 catchments in the forested headwaters and a mixed landscape of the Willamette River Basin, Oregon, based on two years of monitoring. This dissertation contributes three major findings. First, freezing of water alters DOM chemistry by preferentially precipitating aromatic DOM. Second, UV and fluorescent spectroscopy was able to discriminate DOM delivered from highly processed, proteinrich deep subsurface sources during dry seasons especially in forested headwater streams of the H. J. Andrews Experimental Forest (HJA), where nitrogen inputs are very low. In addition, fluorescent DOM chemistry differed among watersheds with varying forest management history. Third, although fluorescent DOM in a headwater forested system differed among land use history, fluorescent DOM composition did not vary among streams draining a well-mixed landscape of urban, pasture/hay, forest, and agricultural land cover types in the central Willamette River Basin, where nitrogen inputs to streams are relatively high. Dissolved organic carbon (DOC) concentration decreased and the fluorescent index indicated an increase in terrestrial sources of DOM from small (1st and 2nd order) to large (4th to 6th order) streams. A protein-like DOM component that was detected in the headwater forested study site (HJA) was not detected in stream samples from the middle basin study site. These findings indicate that in-stream respiration, fueled by nutrient additions from agriculture runoff, consumes bioavailable, labile DOM (proteins) preferentially relative to more recalcitrant, terrestrial sources of DOM along water flow paths from headwater streams to major rivers. This study shows the clear applicability of the fluorescent characterization of DOM in identifying hydrologic and landscape controls as well as varying DOM chemistry and functions throughout watershed ecosystems.

Resolving Spatial and Temporal Variability in Dissolved Organic Matter Characteristics Within Combined Agricultural and Stormwater Conveyances

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Author : Bryce A. Mihalevich
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (1 download)

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Book Synopsis Resolving Spatial and Temporal Variability in Dissolved Organic Matter Characteristics Within Combined Agricultural and Stormwater Conveyances by : Bryce A. Mihalevich

Download or read book Resolving Spatial and Temporal Variability in Dissolved Organic Matter Characteristics Within Combined Agricultural and Stormwater Conveyances written by Bryce A. Mihalevich and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In many urban areas, stormwater runoff can threaten the ecological health of streams and downstream water bodies. Due to the increased impervious nature of urban landscapes, runoff is more 0́−flashy0́+ and as a result, high concentrations of pollutants can be transported in shorter periods of time than in more natural environments. One pollutant of concern is dissolved organic matter (DOM). DOM is important within aquatic ecosystems, but excess amounts can cause depletion in dissolved oxygen concentrations and can negatively affect aquatic organisms. This study investigated changes in DOM quantity and sources within the Northwest Field Canal (NWFC), an urban water conveyance located in Logan, Utah, USA that receives runoff during storm events. DOM was monitored at upstream and downstream locations within the canal and at selected stormwater outfalls within the study reach. During storm events, DOM concentrations were rapidly elevated to values orders of magnitude greater than in baseflow measurements, and were greater at the downstream site than at the upstream site, triggered by contributions from outfalls discharging into the canal. Changes in DOM composition during storm events confirmed that DOM is more terrestrially derived, whereas it is normally more microbially derived during baseflow conditions in the canal. These results provide better understanding of the composition of DOM in the canal system and may provide crucial information for future management of stormwater runoff that can potentially lead to the improvements of water quality in downstream water bodies.

Subsurface Hydrological Responses to Land Cover and Land Use Changes

Author : Makoto Taniguchi
Publisher : Springer Science & Business Media
ISBN 13 : 1461561418
Total Pages : 232 pages
Book Rating : 4.4/5 (615 download)

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Book Synopsis Subsurface Hydrological Responses to Land Cover and Land Use Changes by : Makoto Taniguchi

Download or read book Subsurface Hydrological Responses to Land Cover and Land Use Changes written by Makoto Taniguchi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since human beings first appeared on the earth, we have changed land cover and land use for our own purposes, such as conveniences and high productivity. As a result of the land cover and land use changes, many serious environmental problems occur on the earth. Studying meteorological and hydrological effects of vegetation and land cover/use changes helps us to understand the environmental changes and problems happening near the earth surface, because the vegetation distributes the solar energy and water on the earth surface into atmosphere and geosphere. Subsurface hydrological responses to land cover and land use changes have drawn only regional environmental concerns, although global change caused by biosphere change has been studied in various scientific fields. The changes in land cover and land use alter water, solute and heat cycles in basins and elements of those balances, including evapotranspiration, groundwater recharge rate, discharge rates into rivers or ocean and soil moisture content, which are directly or indirectly related to the global environmental issues. Therefore, the changes in biosphere may substantially alter the subsurface hydrological system. For instance, increased groundwater recharge rates following clearing forest into grasses might be one consequence resulting in rising water tables and salinization.

Stream Ecosystems in a Changing Environment

Author : Jeremy B. Jones
Publisher : Elsevier
ISBN 13 : 0124059198
Total Pages : 566 pages
Book Rating : 4.1/5 (24 download)

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Book Synopsis Stream Ecosystems in a Changing Environment by : Jeremy B. Jones

Download or read book Stream Ecosystems in a Changing Environment written by Jeremy B. Jones and published by Elsevier. This book was released on 2016-07-07 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stream Ecosystems in a Changing Environment synthesizes the current understanding of stream ecosystem ecology, emphasizing nutrient cycling and carbon dynamics, and providing a forward-looking perspective regarding the response of stream ecosystems to environmental change. Each chapter includes a section focusing on anticipated and ongoing dynamics in stream ecosystems in a changing environment, along with hypotheses regarding controls on stream ecosystem functioning. The book, with its innovative sections, provides a bridge between papers published in peer-reviewed scientific journals and the findings of researchers in new areas of study. Presents a forward-looking perspective regarding the response of stream ecosystems to environmental change Provides a synthesis of the latest findings on stream ecosystems ecology in one concise volume Includes thought exercises and discussion activities throughout, providing valuable tools for learning Offers conceptual models and hypotheses to stimulate conversation and advance research

Advances in the Physicochemical Characterization of Dissolved Organic Matter

Author : Fernando Rosario-Ortiz
Publisher : ACS Symposium
ISBN 13 : 9780841229518
Total Pages : 0 pages
Book Rating : 4.2/5 (295 download)

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Book Synopsis Advances in the Physicochemical Characterization of Dissolved Organic Matter by : Fernando Rosario-Ortiz

Download or read book Advances in the Physicochemical Characterization of Dissolved Organic Matter written by Fernando Rosario-Ortiz and published by ACS Symposium. This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of dissolved organic matter (DOM) has fascinated scientists and engineers for at least 60 years - from the initial efforts focused on measuring the concentrations of carbon in marine and aquatic systems, to the discovery of the role of DOM in the formation of disinfection byproducts, all the way to the new emphasis on the detailed understanding of the different functional groups and basic structural features which are the basis for the physicochemical properties of the material. After 50 years of work in the area, there are still many questions regarding DOM. The study of dissolved organic matter (DOM) has fascinated researchers in different fields of science and engineering for many decades. The impact that DOM has on a wide array of environmental processes has resulted in the development of a multidisciplinary community of researchers all focusing on using different analytical techniques and experimental design to better understand DOM. This book offers select case studies focusing on the advanced characterization of DOM in different environments and with respect to different processes. It results from the conclusion of a symposium that E. M. Thurman and I had organized for the 245th meeting of the American Chemical Society, which was held on April 7-11, 2013 in New Orleans, Louisiana.

Dissolved Organic Matter Fluctuations in an Intermittent Headwater Stream

Author : Alba Guarch Ribot
Publisher :
ISBN 13 :
Total Pages : 177 pages
Book Rating : 4.:/5 (12 download)

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Book Synopsis Dissolved Organic Matter Fluctuations in an Intermittent Headwater Stream by : Alba Guarch Ribot

Download or read book Dissolved Organic Matter Fluctuations in an Intermittent Headwater Stream written by Alba Guarch Ribot and published by . This book was released on 2017 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Dissolved organic matter (DOM) is an important source of carbon for aquatic microorganisms and it regulates many biogeochemical processes. Therefore, changes in river DOM concentration and properties could notably affect the functioning of fluvial and coastal ecosystems and alter the global carbon cycle. The DOM in headwater streams is strongly influenced by hydrology, as a consequence of the modification of catchment flow paths with high discharges. During storm events, the catchment hillsides are washed and terrigenous DOM is transported to rivers. In the Mediterranean region, the precipitation regime and evapotranspiration strongly modulate fluvial hydrology, which shows low discharges in summer and even flow disappearance. These dry–wet cycles of conditions affect many ecological and biogeochemical processes. In this thesis, I analyse a long time series of discharge and DOM data from Fuirosos, an intermittent headwater stream in NE Spain. My aim is to examine the relationship between DOM and hydrology at different temporal scales. First, I characterise the hydrological regime of this Mediterranean stream. A decrease in discharge was revealed, although trends in temperature and precipitation were not significant. In contrast, I did not find a clear temporal trend in dry period duration. However, rewetting has been significantly delayed, moving from September to October. The frequency of storm events decreased over the interval 1998–2015, showing a significant positive relationship with solar activity with a 2-year lag. Dissolved organic carbon (DOC) concentration saw a slight decrease during the study period, which was opposed to that observed in boreal systems. This pattern might respond to a reduction of terrigenous DOC input from forest hillsides as a consequence of the decrease in flushing episodes. The DOC temporal dynamics during the rewetting was regulated by dry period duration. Discharge oscillations explained up to 50% of total DOC variability during the wet period. Notably, this weight of discharge increased significantly over the years. DOM quality was also explored, and described in terms of absorbance and fluorescence properties. Most of the DOM properties were strongly related to discharge, revealing the input of allochthonous, degraded, aromatic, humic and large-molecular DOM under high flow conditions. However, these relationships were altered during drying and rewetting periods. The DOM responses at the individual storm event scale were highly heterogeneous. Multiple linear regression and commonality analyses showed that, in addition to the magnitude of storm episodes, antecedent hydrological conditions, namely pre-event basal flow and the magnitude of the previous storm event, played a significant role in regulating the trends and shapes of DOM–discharge hysteresis. Finally, I identified the differences and similarities in the DOM–discharge relationships between the intermittent Mediterranean stream analysed herein and a perennial Alpine stream with higher mean discharge (Oberer Seebach). The DOM in Fuirosos was significantly more concentrated, more terrigenous, more degraded, more aromatic and more humified. The sign of the global DOM–discharge response was the same in both streams. However, discharge was a more robust predictor of DOM variability in Oberer Seebach. In fact, low flow and rewetting periods in Fuirosos introduced considerable dispersion into the relationship. During snowmelt in Oberer Seebach the sensitivity to discharge also decreased or disappeared. The flushing/dilution patterns were essentially associated with the magnitude of storm events in Fuirosos. In contrast, the DOM quality change was more coupled to basal flow conditions in Oberer Seebach, while the storms were behind the DOC oscillations. This study attests to the importance of generating and analysing long-term and high-frequency biogeochemical series, which allow relationships between DOM and hydrology to be explored in intermittent headwater streams that are subjected to extreme hydrological regimes." -- TDX.

Aquatic Ecosystems: Interactivity of Dissolved Organic Matter

Author : Stuart Findlay
Publisher : Academic Press
ISBN 13 : 0122563719
Total Pages : 534 pages
Book Rating : 4.1/5 (225 download)

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Book Synopsis Aquatic Ecosystems: Interactivity of Dissolved Organic Matter by : Stuart Findlay

Download or read book Aquatic Ecosystems: Interactivity of Dissolved Organic Matter written by Stuart Findlay and published by Academic Press. This book was released on 2003 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: Overviews of the source, supply and variability of DOM, surveys of the processes that mediate inputs to microbial food webs, and syntheses consolidating research findings provide a comprehensive review of what is known of DOM in freshwater. This book will be important to anyone interested in understanding the fundamental factors associated with DOM that control aquatic ecosystems."--BOOK JACKET.

Watershed Hydrology

Author : Vijay P. Singh
Publisher : Allied Publishers
ISBN 13 : 9788177645477
Total Pages : 588 pages
Book Rating : 4.6/5 (454 download)

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Book Synopsis Watershed Hydrology by : Vijay P. Singh

Download or read book Watershed Hydrology written by Vijay P. Singh and published by Allied Publishers. This book was released on 2003 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Characterization of Dissolved Organic Matter and Determination of Its Biogeochemical Significance in Coastal and Inland Water Bodies

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Author : M.S. Sankar
Publisher :
ISBN 13 :
Total Pages : 153 pages
Book Rating : 4.:/5 (111 download)

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Book Synopsis Characterization of Dissolved Organic Matter and Determination of Its Biogeochemical Significance in Coastal and Inland Water Bodies by : M.S. Sankar

Download or read book Characterization of Dissolved Organic Matter and Determination of Its Biogeochemical Significance in Coastal and Inland Water Bodies written by M.S. Sankar and published by . This book was released on 2019 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissolved organic matter (DOM) is a major component of natural waters and provides essential nutrients for aquatic organisms. However, excess DOM in the water results in water quality issues and affects the aquatic life negatively. The present research evaluated the source, composition, reactivity, dynamics, and the spatial distribution of DOM in diverse water bodies using spectrofluorometric methods in tandem with multivariate statistics. The study was conducted in the inland and coastal water bodies of Mississippi, Louisiana, and Alabama over a period of three years (2016 to 2018). Surface water samples were collected from spatially separated waterbodies with diverse land use and land cover classes. In addition, reactivity of DOM was assessed by conducting a series of laboratory experiments at varying magnitudes of sunlight and bacterial activity. Spatial distribution and mobility of DOM, nutrients and trace elements with respect to land cover classes and hydrology was evaluated using watershed delineation and multivariate statistics. Results suggest that microbial humic-like or protein-like DOM compositions derived from microbial/anthropogenic sources were less reactive than the terrestrial humic-like compositions originated from forests and woody wetlands. Furthermore, the sunlight was the major factor causing the degradation of DOM in the water bodies, while temperature had a minor effect. Additionally, the results also suggest that livestock fields in the pastoral and rangelands release a high amount of microbial humic-like DOM along with nutrients such as phosphates and nitrates into the water bodies. Present research identified the presence of four types of DOM in the study areas and were terrestrial humic-like, microbial humic-like, soil-derived humic-like and protein-like compositions. Additionally, trace element availability and mobility of coastal areas is influenced by local hydrology and precipitation. Research also identified forested areas as the major source of DOM to the water bodies of Mississippi. In conclusion, present research found that watershed land use and land cover, hydrology, and climate control the dynamics of DOM, other nutrients, and trace element delivery to the water bodies, while combined effects of light and bacteria are more efficient in reprocessing DOM chemistry within the waterbody.

Watershed Export of Dissolved Organic Matter in Response to Anthropogenic and Hydroclimatic Drivers in Subtropical Streams and Rivers

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Author : Shuo Chen
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (129 download)

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Book Synopsis Watershed Export of Dissolved Organic Matter in Response to Anthropogenic and Hydroclimatic Drivers in Subtropical Streams and Rivers by : Shuo Chen

Download or read book Watershed Export of Dissolved Organic Matter in Response to Anthropogenic and Hydroclimatic Drivers in Subtropical Streams and Rivers written by Shuo Chen and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissolved organic matter (DOM) is an assemblage of heterogeneous organic compounds that play important roles in terrestrial and aquatic ecosystems. In this dissertation, I investigated changes in the amount, source, composition, lability, and ecological functions of stream water DOM in response to agricultural land use, hydrological events, and downstream transport and transformation in the southeastern United States. The dissertation includes three stand-alone studies presented in Chapters 2, 3 and 4, respectively. In Chapter 2, I evaluated the effects of hurricane-induced storm events on the quantity and quality of DOM exported from ten watersheds of various physical and land-use characteristics within five Gulf and South Atlantic states. We found that large storms can significantly enhance the concentrations and yields of terrestrially-derived dissolved organic carbon (DOC) and nutrients in streams and rivers but decrease the percentage bioreactive DOC. This study demonstrates that extreme weather and climate events can lead to rapid, ecosystem-level disturbances that significantly shift energy and nutrient availability within drainage networks. The objective of Chapter 3 was to quantify the relative importance of agricultural land use and natural hydroclimatic drivers in affecting the quality and quantity of DOM in a group of 15 streams draining watersheds of a gradient of agricultural land use. The partial least square path modeling (PLS-PM) identified that agricultural land use increased stream water DOM quantity primarily through increasing allochthonous carbon sources. This study demonstrates that structural equation modeling is a powerful tool that should be more widely adopted to distinguish among multiple drivers and mechanisms regulating freshwater biogeochemistry. Chapter 4 investigated the longitudinal transformations of DOM in relation to ecosystem metabolism along a fluvial section including 3rd order, 7th and 8th order streams. From upstream to downstream, DOC concentrations and the relative contributions of freshly-produced DOM increased. The gross primary productivity was positively correlated with the contributions of autochthonous DOM, yet the ecosystem respiration did not vary with the quantity or quality of DOM. This study highlights the complexity of DOM transformations in relation to stream metabolism along the river continuum. Collectively, the three independent but connected studies reveal the complexity and sensitivity of inland water DOM in response to hydroclimatic and anthropogenic drivers. The findings provide new insights into potential shifts in energy and substrates exported across the terrestrial-aquatic boundary due to human activities and climate change and how these shifts can alter water quality and fluvial biogeochemical functions.

Seasonal and Spatial Variation in the Chemical Character of Dissolved Organic Matter Within a Small Boreal Forest Watershed

Author : Alexander W. Newman
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (131 download)

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Book Synopsis Seasonal and Spatial Variation in the Chemical Character of Dissolved Organic Matter Within a Small Boreal Forest Watershed by : Alexander W. Newman

Download or read book Seasonal and Spatial Variation in the Chemical Character of Dissolved Organic Matter Within a Small Boreal Forest Watershed written by Alexander W. Newman and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissolved organic matter (DOM) is a significant carbon reservoir and component of the terrestrial-to-aquatic flux (Qualls et al., 1991). The terrestrial-to-aquatic carbon flux, a relatively new addition to global carbon models, is currently estimated to transfer a total of 1.7 petagrams (Pg) carbon (C) yr−1 globally (IPCC, 2013). Terrestrially derived DOM has been identified as a significant pool of organic matter in the aquatic environment. However, the quantity and chemical composition of DOM transferred, as well as the mechanisms driving its transfer, are less understood. This thesis focuses on expanding our knowledge of the processing DOM undergoes as it is transferred from terrestrial-to-aquatic environments by: 1) developing a standardized extraction methodology that can yield representative eluates when applied to sourced samples from throughout the terrestrial-to-aquatic interface and 2) applying the designed methodology to conduct a year long study of DOM quantity and composition in the terrestrial-to-aquatic interface in a boreal forest watershed. Experimental results suggest that although solid phase extraction with a divinyl benzene sorbent (SPE-PPL) yields high extraction efficiencies when applied to DOM, it is subject to selectivity. Extractions performed at high loading volumes were found to select against O-alkyl DOM hydrogen constituents, additionally all SPE-PPL experiments were found to select against nitrogenous DOM components. However, by considering proper extraction parameters, SPE-PPL can produce bulk representative eluates for nuclear magnetic resonance (NMR) analysis from land positions spanning the terrestrial-to-aquatic interface. Results from the field study revealed that DOM transferred from terrestrial-to-aquatic land positions in a boreal forest watershed is both temporally and regionally variable, however, proximity immediately downstream of ponds appeared to be a major hydrologic control, while seasonal variation in hydrologic flow paths may represent another control in boreal forest watersheds. Dissolved organic matter chemical composition and quantity in traditional boreal forest streams related to shifts in the hydraulic flow path of the watershed, indicated by changes in riverine DOM chemical composition that correlated to seasonal wet and dry periods. Increases in both dissolved organic carbon (DOC) concentration and the presence of O-alkyl DOM hydrogen functionalities in the stream indicated a shift from groundwater sources during the dry period to soil water sources during the wet period. Conversely streams downslope of ponds seemed to be buffered against shifts in DOM chemical composition associated with changes in hydrologic flow paths. Dissolved organic matter chemical composition of streams downslope of ponds were relatively constant throughout the year resembling the characterization of pond outflows, even during periods of high hydraulic conductivity, via additions of autochthonous DOM produced in the pond. These additions of autochthonous DOM are negligible in streams not downslope of ponds. Further application of this approach during key periods of DOM export, such as spring snowmelt and fall rain periods may prove help to reveal the processes controlling the terrestrial-to-aquatic carbon flux in boreal forest landscapes.

Subsurface Hydrological Responses to Land Cover and Land Use Changes

Author : Makoto Taniguchi
Publisher : Springer
ISBN 13 : 9781461561422
Total Pages : 226 pages
Book Rating : 4.5/5 (614 download)

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Book Synopsis Subsurface Hydrological Responses to Land Cover and Land Use Changes by : Makoto Taniguchi

Download or read book Subsurface Hydrological Responses to Land Cover and Land Use Changes written by Makoto Taniguchi and published by Springer. This book was released on 2011-09-26 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since human beings first appeared on the earth, we have changed land cover and land use for our own purposes, such as conveniences and high productivity. As a result of the land cover and land use changes, many serious environmental problems occur on the earth. Studying meteorological and hydrological effects of vegetation and land cover/use changes helps us to understand the environmental changes and problems happening near the earth surface, because the vegetation distributes the solar energy and water on the earth surface into atmosphere and geosphere. Subsurface hydrological responses to land cover and land use changes have drawn only regional environmental concerns, although global change caused by biosphere change has been studied in various scientific fields. The changes in land cover and land use alter water, solute and heat cycles in basins and elements of those balances, including evapotranspiration, groundwater recharge rate, discharge rates into rivers or ocean and soil moisture content, which are directly or indirectly related to the global environmental issues. Therefore, the changes in biosphere may substantially alter the subsurface hydrological system. For instance, increased groundwater recharge rates following clearing forest into grasses might be one consequence resulting in rising water tables and salinization.

Linking Optical and Chemical Properties of Dissolved Organic Matter in Natural Waters

Author : Christopher L. Osburn
Publisher : Frontiers Media SA
ISBN 13 : 2889450813
Total Pages : 244 pages
Book Rating : 4.8/5 (894 download)

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Book Synopsis Linking Optical and Chemical Properties of Dissolved Organic Matter in Natural Waters by : Christopher L. Osburn

Download or read book Linking Optical and Chemical Properties of Dissolved Organic Matter in Natural Waters written by Christopher L. Osburn and published by Frontiers Media SA. This book was released on 2017-01-17 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: A substantial increase in the number of studies using the optical properties (absorbance and fluorescence) of dissolved organic matter (DOM) as a proxy for its chemical properties in estuaries and the coastal and open ocean has occurred during the last decade. We are making progress on finding the actual chemical compounds or phenomena responsible for DOM’s optical properties. Ultrahigh resolution mass spectrometry, in particular, has made important progress in making the key connections between optics and chemistry. But serious questions remain and the last major special issue on DOM optics and chemistry occurred nearly 10 years ago. Controversies remain from the non-specific optical properties of DOM that are not linked to discrete sources, and sometimes provide conflicting information. The use of optics, which is relatively easier to employ in synoptic and high resolution sampling to determine chemistry, is a critical connection to make and can lead to major advances in our understanding of organic matter cycling in all aquatic ecosystems. The contentions and controversies raised by our poor understanding of the linkages between optics and chemistry of DOM are bottlenecks that need to be addressed and overcome.

Quantity and Composition of Stream Dissolved Organic Matter in the Watershed of Conesus Lake, New York

Author : Morgan Bida
Publisher :
ISBN 13 :
Total Pages : 116 pages
Book Rating : 4.:/5 (875 download)

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Book Synopsis Quantity and Composition of Stream Dissolved Organic Matter in the Watershed of Conesus Lake, New York by : Morgan Bida

Download or read book Quantity and Composition of Stream Dissolved Organic Matter in the Watershed of Conesus Lake, New York written by Morgan Bida and published by . This book was released on 2013 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The watershed of Conesus Lake, New York is drained by more than 18 unique streams and several smaller tributaries and has multiple land uses, varying from highly agricultural to primarily wooded, making the lake an ideal study site for analysis of the effects of land use on various water quality parameters. Previous water quality and watershed-health studies at Conesus Lake have focused on the delivery of inorganic nutrients to the lake. We know much less, however, about the effects of watershed land use on the quantity and composition of dissolved organic matter (DOM) exported to the lake. We sought to determine how stream DOM quantity and composition varied with space and time within the watershed during 2011. The concentrations of dissolved organic carbon and inorganic and organic nitrogen and phosphorus were measured seasonally in 7 streams, with a more detailed analysis of water chemistry in 12 streams during the growing season. The composition of DOM entering Conesus Lake was assessed with a suite of optical indices and with fluorescence excitation-emission matrices (EEMs) with parallel factor analysis (PARAFAC), a chemometric technique for the decomposition of characteristic fluorescence peaks. A 4-component PARAFAC model showed one allochthonous, humic-like component (C1), one semi-labile component with allochthonous and/or autochthonous origin (C2), and two autochthonous, protein-like components (C3 & C4). We showed seasonality in the composition and quantity of DOM that is consistent with abiotic seasonal controls and principal components analyses (PCA) suggest that agriculturally-dominated streams are associated with increased nitrate and phosphate, a greater proportion of protein-like PARAFAC components (C3 & C4), and that the DOM tends to be less humified. These results imply that a) seasonal controls on DOM govern the abundance of protein-like DOM and can alter the quantity of bulk DOM, b) agricultural land use may augment autochthonous production in a stream, particularly in the spring and summer, thus creating a more labile pool of DOM that is exported to the lake, and c) stream order can alter DOM quantity and composition, possibly through instream processing and variations in light availability."--Abstract.

Dissolved Organic Matter in Atmospheric Deposition

Author : Lidiia Iavorivska
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (971 download)

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Book Synopsis Dissolved Organic Matter in Atmospheric Deposition by : Lidiia Iavorivska

Download or read book Dissolved Organic Matter in Atmospheric Deposition written by Lidiia Iavorivska and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissolved organic matter (DOM) in the atmosphere affects air quality and climate. Unlike inorganic constituents that typically consist of single compounds, DOM is a mixture of multiple organic compounds having varying molecular weights, reactivity and solubility. Dissolved organic carbon (DOC) is typically used as a measure of the total DOM present in solution. In the atmosphere, DOC originates from emissions of various biogenic and anthropogenic sources, such as vegetation, incomplete combustion of fossil fuels, biomass burning, and sea-spray. The ultimate fate of atmospheric DOC is to be oxidized to inorganic forms of carbon dioxide and carbon monoxide, or to be removed from the atmosphere and transferred to the landscape through deposition. Deposition can occur as wet deposition via precipitation and as dry deposition via surface settling of particles and gases. The concentration, or quantity, of DOC in precipitation plays an important role in the carbon cycle and in other elemental cycles; while the chemical composition, or quality, of DOC in precipitation largely determines its fate in the environment. Rain and snow deposited to the landscape are a source of nutrient enrichment to ecosystems and water bodies, and are especially important as an input of carbon in coastal regions. Since DOC in precipitation is highly chemically reactive and bioavailable it influences rates of productivity in aquatic ecosystems. Despite the significance of DOC to many ecosystem processes, knowledge about its contributions to landscapes in precipitation remains limited. With anthropogenic influences on the carbon cycle now widely recognized, the need for synthesis of existing datasets on atmospheric deposition of DOC and further determining its rates and drivers is great. My dissertation is focused on wet deposition of DOC and assesses the magnitude and patterns of variation of organic matter in precipitation over space and time. The dissertation is organized into four manuscripts. Chapter 1 is a literature review where I provide a new data synthesis from 83 contemporary, peer-reviewed studies where organic carbon (OC) in precipitation was measured at sites around the world. Data regarding the concentrations of OC in precipitation and rates of atmospheric deposition were compiled in a common set of units and presented along with the summary statistics. These data give insights into the magnitude and regional variability of OC in precipitation. Organic carbon was ubiquitous in precipitation in rural and urban locations; with DOC in precipitation spanning several orders of magnitude between locations. This synthesis brings attention to atmospheric deposition as an under-sampled piece of the global carbon cycle; highlights gaps in data availability and challenges for data inter-comparison; and provides a unique data set that can be used for toward exploring future changes in the carbon cycle. Chapter 2 aims to understand how DOC concentration and composition in precipitation change temporally from storm to storm. Precipitation samples were collected at the Susquehanna Shale Hills Critical Zone Observatory watershed (Pennsylvania, USA) during 90 storm events. Observational data revealed temporal variability associated with seasonality and meteorological conditions. Using a mixed modeling statistical approach, I showed that there are multiple processes that work in synergy to influence the quantity and quality of DOC in precipitation. Factors related to storm properties, emission sources, and to the chemical composition of the atmosphere could explain more than 60% of the storm to storm variability in DOC concentrations. This study provided observations on changes in DOC that can be useful in modeling of atmospheric chemistry and in considering temporal changes in ecosystem nutrient balances and microbial activity.Chapter 3 explores how DOC concentration and composition vary throughout the course of storm events. I measured DOC in sequential samples during 13 storms at the Shale Hills watershed. The observational data generated hypotheses about potential factors that influence variability of DOC within storms. While previous studies have observed that concentrations of other elements in precipitation typically decrease over the course of individual storms, results from this study showed that DOC concentrations are highly variable. During most storms concentrations decreased towards the end of the event; however increasing concentrations in the later stages of some storms highlight that DOC removal with precipitation is not merely an exponential decay process. The variability of DOC during events is related to the balance between the cloud microphysics, atmospheric chemical transformations, and synoptic scale gradients in the abundance of organic compounds in the boundary layer. This work advances understanding of physicochemical processes occurring during storms that are relevant to studies of atmospheric chemistry, carbon cycling, and ecosystem responses.Chapter 4 quantifies spatial gradients in wet atmospheric DOC deposition across the state of Pennsylvania (USA). DOC concentrations were measured in selected precipitation samples collected for six years at a network of atmospheric deposition monitoring sites. A simple modeling approach was used to estimate the first statewide, annual estimates of wet atmospheric DOC deposition. Results showed that DOC inputs with wet deposition in Pennsylvania represented about one-third as much as literature reported values for DOC exported by rivers from watersheds in the region. The rates of DOC wet deposition showed a pronounced seasonality and spatial distribution, with highest deposition rates observed in the summer, especially at the sites located in western Pennsylvania.

Chemical Biomarkers in Aquatic Ecosystems

Author : Thomas S. Bianchi
Publisher : Princeton University Press
ISBN 13 : 1400839106
Total Pages : 417 pages
Book Rating : 4.4/5 (8 download)

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Book Synopsis Chemical Biomarkers in Aquatic Ecosystems by : Thomas S. Bianchi

Download or read book Chemical Biomarkers in Aquatic Ecosystems written by Thomas S. Bianchi and published by Princeton University Press. This book was released on 2011-02-28 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook provides a unique and thorough look at the application of chemical biomarkers to aquatic ecosystems. Defining a chemical biomarker as a compound that can be linked to particular sources of organic matter identified in the sediment record, the book indicates that the application of these biomarkers for an understanding of aquatic ecosystems consists of a biogeochemical approach that has been quite successful but underused. This book offers a wide-ranging guide to the broad diversity of these chemical biomarkers, is the first to be structured around the compounds themselves, and examines them in a connected and comprehensive way. This timely book is appropriate for advanced undergraduate and graduate students seeking training in this area; researchers in biochemistry, organic geochemistry, and biogeochemistry; researchers working on aspects of organic cycling in aquatic ecosystems; and paleoceanographers, petroleum geologists, and ecologists. Provides a guide to the broad diversity of chemical biomarkers in aquatic environments The first textbook to be structured around the compounds themselves Describes the structure, biochemical synthesis, analysis, and reactivity of each class of biomarkers Offers a selection of relevant applications to aquatic systems, including lakes, rivers, estuaries, oceans, and paleoenvironments Demonstrates the utility of using organic molecules as tracers of processes occurring in aquatic ecosystems, both modern and ancient