The Effects Of Agricultural Land Use On Stream Ecosystem Functioning Dynamics Of Organic Carbon And Food Web Processes
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The Effects Of Agricultural Land Use On Stream Ecosystem Functioning Dynamics Of Organic Carbon And Food Web Processes
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Author : Romy Wild
language : en
Publisher:
Release Date : 2023
The Effects Of Agricultural Land Use On Stream Ecosystem Functioning Dynamics Of Organic Carbon And Food Web Processes written by Romy Wild and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2023 with categories.
Restoring Connectivity The Effect Of Riparian Replanting On In Stream Organic Carbon Dynamics In A Degraded Agricultural Landscape
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Author : Darren Paul Giling
language : en
Publisher:
Release Date : 2014
Restoring Connectivity The Effect Of Riparian Replanting On In Stream Organic Carbon Dynamics In A Degraded Agricultural Landscape written by Darren Paul Giling and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014 with categories.
Streams and rivers are intrinsically linked to the terrestrial environment by the exchange of water, nutrients, organic matter and biota. Terrestrial-aquatic connectivity has been disrupted by the degradation and removal of riparian vegetation due to widespread agricultural development. Loss of terrestrial vegetation modifies channel shading, in-stream habitat, and the quantity and composition of organic carbon (i.e. energy) subsidies provided to stream food webs. Collectively, these changes result in biodiversity loss and altered ecosystem functioning.Replanting riparian vegetation aims to alleviate the adverse ecological effects of riparian clearance. Replanting is already commonly used for ecological restoration, but revegetation may become more widespread if restoration activities are driven by economic forces, such as payments for planting trees to mitigate climate change. However, replantings currently are often spatially limited and isolated, so the plantings may not have a large effect on halting or reversing ecological degradation.Riparian clearance and revegetation are likely to alter carbon dynamics, which is a critical process underpinning biodiversity and ecosystem functioning in streams. We have little knowledge of if, and when, riparian replanting will restore in-stream organic-carbon processes towards pre-clearance conditions, or of the broad-scale effects on carbon balances. The integration of aquatic fluxes into regional carbon budgets is an important component of regional, national and global carbon accounting. I sought to: (1) quantify the reach-scale effects of replanting on in-stream organic carbon dynamics; (2) assess the potential for organic matter properties to reflect the success of restoring terrestrial-aquatic connectivity; and (3) upscale organic carbon fluxes to project the consequences of revegetation for carbon balance and atmospheric feedback at watershed (= catchment) scales.I assessed the dynamics of aquatic organic carbon (input, standing stock, export and metabolism) in 15 streams (1st-3rd Strahler order) of an agricultural landscape in south-eastern Australia. Ten of the streams had reaches that were replanted with native woody vegetation 8 to 22 years prior to the study; I refer to these restored reaches as 'replanted' and other reaches in which there had been no plantings, pasture reaches, as 'untreated'.Replanted stream reaches had greater inputs and accumulation of terrestrial organic carbon on the stream-bed than did untreated reaches. Replanting was correlated with a reduction in net ecosystem productivity and a shorter organic carbon turnover length. Within two decades of planting, metabolic rates in replanted reaches had values more typical of those in natural, forested streams, supporting the use of ecosystem metabolism as a functional indictor of restoration success at reach-scales. Metabolic measures could be combined with pattern-based measures, such as biodiversity, to demonstrate the ecological value of replanting.The export of organic carbon was governed by land-use and climatic variables at spatial scales larger than typical replanting projects. Watershed tree cover affected the composition of dissolved organic matter, but not its quantity. A greater proportion of the dissolved organic matter in agricultural streams was from within the stream and a reduced proportion was from terrestrial vegetation, compared to streams in forested watersheds. The characteristics of dissolved organic matter potentially provide an aggregate measure of aquatic and terrestrial connectivity over large spatial scales. The quantity of total organic carbon transported was controlled by discharge. Projected increases in rainfall variability will affect the timing and magnitude of storm-flows, altering the fluxes of energy subsidies among ecosystems in landscapes.The estimated organic carbon budget showed that replanted reaches potentially were a greater source of carbon than were untreated reaches (net change -0.52 g C m-2 day-1 ± 0.80 SD). At a watershed scale, this increased carbon loss per unit area of stream was small compared to organic carbon export from 3rd-order streams. Riparian restoration at reach spatial scales (i.e. 100s of m) can restore ecosystem processes towards pre-clearance condition, within two decades. However, the effects of replanting at small scales may be overwhelmed by changes to hydrologic processes arising from probable increased climate variability in the future. Addressing land-use effects requires a landscape perspective that incorporates spatial context and connectivity at multiple scales to guide restoration activities into the areas likely to provide the greatest ecological return for investment.
Methods In Stream Ecology
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Author : F. Richard Hauer
language : en
Publisher: Academic Press
Release Date : 2017-05-15
Methods In Stream Ecology written by F. Richard Hauer and has been published by Academic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017-05-15 with Science categories.
Methods in Stream Ecology: Volume 2: Ecosystem Structure, Third Edition, provides a complete series of field and laboratory protocols in stream ecology that are ideal for teaching or conducting research. This new two-part edition is updated to reflect recent advances in the technology associated with ecological assessment of streams, including remote sensing. Volume two covers community interactions, ecosystem processes and ecosystem quality. With a student-friendly price, this new edition is key for all students and researchers in stream and freshwater ecology, freshwater biology, marine ecology and river ecology. This book is also supportive as a supplementary text for courses in watershed ecology/science, hydrology, fluvial geomorphology and landscape ecology. Provides a variety of exercises in each chapter Includes detailed instructions, illustrations, formulae and data sheets for in-field research for students Presents taxonomic keys to common stream invertebrates and algae Includes website with tables and a links written by leading experts in stream ecology
Stream Ecology
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Author : J. David Allan
language : en
Publisher: Springer Science & Business Media
Release Date : 2007-08-17
Stream Ecology written by J. David Allan and has been published by Springer Science & Business Media this book supported file pdf, txt, epub, kindle and other format this book has been release on 2007-08-17 with Science categories.
A hugely important text for advanced undergraduates as well as graduates with an interest in stream and river ecology, this second, updated edition is designed to serve as a textbook as well as a working reference for specialists in stream ecology and related fields. The book presents vital new findings on human impacts, and new work in pollution control, flow management, restoration and conservation planning that point to practical solutions. All told, the book is expanded in length by some twenty-five percent, and includes hundreds of figures, most of them new.
Fundamentals Of Ecosystem Science
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Author : Kathleen C. Weathers
language : en
Publisher: Elsevier
Release Date : 2021-07-26
Fundamentals Of Ecosystem Science written by Kathleen C. Weathers and has been published by Elsevier this book supported file pdf, txt, epub, kindle and other format this book has been release on 2021-07-26 with Science categories.
Fundamentals of Ecosystem Science, Second Edition provides a comprehensive introduction to modern ecosystem science covering land, freshwater and marine ecosystems. Featuring full color images to support learning and written by a group of experts, this updated edition covers major concepts of ecosystem science, biogeochemistry, and energetics. Case studies of important environmental problems offer personal insights into how adopting an ecosystem approach has helped solve important intellectual and practical problems. For those choosing to use the book in a classroom environment, or who want to enrich further their reading experience, teaching and learning assets are available at Elsevier.com. Covers both aquatic (freshwater and marine) and terrestrial ecosystems with updated information Includes a new chapter on microbial biogeochemistry Features vignettes throughout the book with real examples of how an ecosystem approach has led to important change in policy, management, and ecological understanding Demonstrates the application of an ecosystem approach in synthesis chapters and case studies Contains new coverage of human-environment interactions
Effects Of Agricultural Land Use On Dissolved Organic Carbon And Nitrogen In Streams
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Author : Marlen Heinz
language : en
Publisher:
Release Date : 2016
Effects Of Agricultural Land Use On Dissolved Organic Carbon And Nitrogen In Streams written by Marlen Heinz and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with categories.
Dynamics In Organic Matter Processing Ecosystem Metabolism And Tropic Sources For Consumers In The Mara River Kenya
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Author : Frank Onderi Masese
language : en
Publisher: CRC Press
Release Date : 2015-05-01
Dynamics In Organic Matter Processing Ecosystem Metabolism And Tropic Sources For Consumers In The Mara River Kenya written by Frank Onderi Masese and has been published by CRC Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015-05-01 with Science categories.
To properly conserve, restore and manage riverine ecosystems and the services they provide, it is pertinent to understand their functional dynamics. Growing human populations and high dependency on natural resources in developing countries have exerted pressure on land and water resources. However, there is a major knowledge gap concerning the influence of human activities on the functioning of tropical rivers in terms of organic matter processing and energy sources supporting riverine consumers. This thesis explores the functioning of tropical upland streams and savanna rivers by assessing the spatial and temporal dynamics in organic processing under different land-use and discharge conditions and the resultant influence on energy sources for riverine consumers. This thesis contributes to the theories of river functioning and has improved understanding of the functioning of African tropical streams by identifying a diverse macroinvertebrate shredder guild and determining its role in organic matter processing. This thesis also shows that large mammalian herbivores enhance terrestrial-aquatic food web linkages in African savanna rivers via the transfer of organic matter. The findings of this researcht are useful for defining future research needs and actions for sustainable management of agriculturally influenced streams and savanna rivers in landscapes witnessing declining wildlife populations and changing land uses.
Comparing Hypotheses Proposed By Two Conceptual Models For Stream Ecology
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Author : Sean E. Collins
language : en
Publisher:
Release Date : 2014
Comparing Hypotheses Proposed By Two Conceptual Models For Stream Ecology written by Sean E. Collins and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014 with categories.
The broad goal of stream ecology is to understand and predict complex interactions between environmental factors and processes that occur within streams and rivers, such as biological community composition and their interactions, system metabolism (productivity and respiration), and nutrient sources and concentration. Multiple factors are thought to play important roles in these processes including regional environmental conditions (i.e., hydrology, geology, stream form/morphology) and longitudinal position within a stream network (defined by Strahler stream order). In the past, several theoretical concepts have been proposed to attempt to describe and explain how streams behave, and each concept uses various factors weighted differently to characterize streams and gain a better understanding of ecological processes and overall system functions. Here, two differing theories of stream ecology are compared - the River Continuum Concept (RCC) and the Riverine Ecosystem Synthesis (RES). Each of these theories has unique predictions based on either Strahler stream order (SSO; used by the RCC) or functional process zone (FPZ; used by the RES) defined by hydrogeomorphic characteristics. Predictions from both theories were tested across sites representing multiple SSOs and FPZs within the Kanawha River Basin. Measures of environmental heterogeneity (an important concept for differentiating between FPZs) were also assessed. This project has shown that some predictions from both the RCC and the RES are valid. The physical character of the basin is variable; sampling of riverbed substratum at each site revealed that similarities within each FPZ in riverbed composition exist and that each FPZ is distinct. Hydrogeomorphic factors including underlying geology and valley floor width strongly influence the character of the riverbed substratum. The ratio of primary productivity to ecosystem respiration (i.e., a measure of metabolism) aligned with predictions from the RES where potential light availability and environmental heterogeneity were major drivers of this ratio. On the other hand, a "sliding scale" (i.e., one that changes with environmental variables) may be more appropriate for predictions from the RCC as the apparent trend toward higher rates of primary productivity was shifted from mid-order to larger streams. Neither the RCC nor the RES provide clear hypotheses for fluctuations in nutrient concentrations, and changes in these concentrations were not accurately explained by either SSO or FPZ. Finally, results from stable isotope analysis of carbon and nitrogen revealed that consumers in the Kanawha River Basin utilize a combination of aquatic and terrestrial organic carbon. While food web metrics and the proportional dependence upon in-stream and terrestrially derived carbon follow predictions of the RCC more closely, the mechanisms underlying these predictions are not always met. That is, there was no relationship between high measured rates of aquatic primary productivity and low dependence on terrestrial carbon sources. The RES also explains well the shift in organic carbon use from various sources by consumers. Perhaps the best model for understanding these processes is a combination of both concepts. Understanding the reasons for changes in processes and functions within streams and rivers is critical for developing a useful and successful model. It is through this process of model conceptualization, testing, and refining that true advancements in knowledge can take place.
Microbial Diversity And Ecosystem Functioning In Fragmented Rivers Worldwide
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Author : Lunhui Lu
language : en
Publisher: Frontiers Media SA
Release Date : 2023-11-27
Microbial Diversity And Ecosystem Functioning In Fragmented Rivers Worldwide written by Lunhui Lu and has been published by Frontiers Media SA this book supported file pdf, txt, epub, kindle and other format this book has been release on 2023-11-27 with Science categories.
Dams or barriers are among the most significant anthropogenic threats to global freshwater ecosystems, although they provide invaluable services for shipping, hydropower generation, flood protection, and storage of drinking and irrigation water. River fragmentations due to dams and barriers lead the aquatic landscape into isolated river sections, resulting in hydromorphological discontinuities along longitudinal or lateral gradients. Fragmented river habitats are unstable. They experience uncertain disturbances in both time and space with random and complex hydrological and environmental processes, such as water flow, particulate matter sedimentation, reservoir regulation, and terrestrial input. The diversity, composition, functionality, and activity of microbial communities are important indicators of river ecosystem functions and services. Yet, river fragmentations are likely to disrupt and reconstruct microbial communities, redirecting the patterns of biogeochemical cycles of biogenic elements. Methodology, such as mathematical models, is still limited to describing and elucidating microbial processes under changing hydrological environments in the fragmented rivers. Thus, how do the riverine microbial communities and ecosystem functions respond to the fragmentation in rivers? This Research Topic represents a collective focus on microbial ecology, functional diversity, and new microbial modeling in fragmented rivers. We wish to present new findings in community assembly mechanisms, biotic interactions, functional diversity, and ecosystem functioning responses to the river fragmentations. New perspectives will also provide us with deep insights into the ecological effects of river fragmentation. This Research Topic aims to present the original research articles and reviews to provide new findings on microbial diversity and ecosystem functioning in fragmented rivers worldwide. We welcome original research, reviews, mini-reviews, opinions, methods, hypotheses and theories, and perspectives. The directions include but are not limited to the following aspects: - The continuum of the microbial community in responses to dams or barriers. - Novel microbial community assembly mechanisms, functional traits, and biotic interactions in fragmented rivers at local, regional, and global scales. - Functional genes, functional groups, and functional diversity in driving biogenic element cycles. - Mathematical modeling in aquatic microbial ecology.
The Consequences Of Land Use On Subsidies Of Stream Insects To Terrestrial Consumers
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Author : Ramsa Chaves-Ulloa
language : en
Publisher:
Release Date : 2015
The Consequences Of Land Use On Subsidies Of Stream Insects To Terrestrial Consumers written by Ramsa Chaves-Ulloa and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015 with categories.
"The image of a child standing at the side of a creek and skipping stones across it exemplifies how we tend to mentally separate aquatic habitats from dry land. But there is a constant exchange of materials from land to streams, and vice-versa. Ecologists have long recognized the importance of this material exchange, however most of our knowledge on aquatic terrestrial linkages comes from research developed in temperate, forested sites. Undisturbed, forested areas are becoming increasingly rare, however, thus there is a gap in our understanding of how the movement of materials from streams to land affects riparian food webs in systems affected by land-use change, particularly in the tropics. Moreover, research into aquatic-terrestrial linkages tends to focus on "good" subsidies such as carbon and nutrients, but "bad" subsidies, such as methylmercury, are also exported from streams to land. Through several large scale field studies I explore and elucidate how land-use change affects aquatic-terrestrial linkages and the effects on riparian food webs. My results suggest that agricultural land-use below 60% is associated with changes in the composition of stream subsidies to land via changes in the community of benthic invertebrates. However, agriculture was not associated with changes in the magnitude of the subsidy to land. In the Costa Rica system, the magnitude of the subsidy increases with catchment area, a variable associated with increased nutrients. Additionally, my results show that the stream subsidy affects the community of riparian invertebrate predators in tropical dry forest streams. Finally, my results suggest that changes in dissolved organic carbon modulate the movement of methylated mercury from streams to terrestrial consumers. Taken together, this dissertation increase our understanding of aquatic-terrestrial linkages in the context of human activities, and highlights the importance of these subsidies for terrestrial consumers."