The globally important nature of wetland ecosystems has led to their increased protection and restoration as well as their use in engineered systems. Underpinning the beneficial functions of wetlands are a unique suite of physical, chemical, and biological processes that regulate elemental cycling in soils and the water column. This book provides an in-depth coverage of these wetland biogeochemical processes related to the cycling of macroelements including carbon, nitrogen, phosphorus, and sulfur, secondary and trace elements, and toxic organic compounds.
In this synthesis, the authors combine more than 100 years of experience studying wetlands and biogeochemistry to look inside the black box of elemental transformations in wetland ecosystems. This new edition is updated throughout to include more topics and provide an integrated view of the coupled nature of biogeochemical cycles in wetland systems. The influence of the elemental cycles is discussed at a range of scales in the context of environmental change including climate, sea level rise, and water quality. Frequent examples of key methods and major case studies are also included to help the reader extend the basic theories for application in their own system. Some of the major topics discussed are
Flooded soil and sediment characteristics
Aerobic-anaerobic interfaces
Redox chemistry in flooded soil and sediment systems
Anaerobic microbial metabolism
Plant adaptations to reducing conditions
Regulators of organic matter decomposition and accretion
Major nutrient sources and sinks
Greenhouse gas production and emission
Elemental flux processes
Remediation of contaminated soils and sediments
Coupled C-N-P-S processes
Consequences of environmental change in wetlands#
The book provides the foundation for a basic understanding of key biogeochemical processes and its applications to solve real world problems. It is detailed, but also assists the reader with box inserts, artfully designed diagrams, and summary tables all supported by numerous current references. This book is an excellent resource for senior undergraduates and graduate students studying ecosystem biogeochemistry with a focus in wetlands and aquatic systems.
Author(s): K. Ramesh Reddy, Ronald D. DeLaune, Patrick W. Inglett
Edition: 2
Publisher: CRC Press
Year: 2022
Language: English
Pages: 732
City: Boca Raton
Cover
Half Title
Title
Copyright
Contents
Preface
Acknowledgments
Authors
Chapter 1 Introduction
Chapter 2 Basic Concepts and Terminology
2.1 Introduction
2.2 Chemistry
2.2.1 Aqueous Chemistry
2.2.1.1 Concentration Units
2.2.2 Acids and Bases
2.2.3 Equilibrium Constant
2.2.4 Thermodynamics
2.2.4.1 Influence of pH
2.2.5 Oxidation–Reduction Reactions
2.2.5.1 Oxidation–Reduction
2.2.5.2 Oxidation State or Number
2.2.6 Balancing Oxidation–Reduction Reactions
2.3 Biology
2.3.1 Microbial Cell
2.3.2 Microbial Classification
2.3.3 Chemistry of Biological Molecules
2.3.4 Metabolic Reactions
2.3.5 Enzymes
2.3.6 Biochemical Kinetics
2.4 Isotopes
2.4.1 Radioactive Isotopes and Decay
2.4.2 HalfLife
2.4.3 Stable Isotopes
2.5 Terminology in Soil Science
2.5.1 Master Soil Horizon
2.5.2 Properties Used in Soil Description
2.5.3 Soil Taxonomy
2.5.4 Physical Properties
2.5.5 Chemical Properties
2.6 Units
Study Questions
Further Readings
Chapter 3 Biogeochemical Characteristics
3.1 Introduction
3.2 Types of Wetlands
3.2.1 Coastal Wetlands
3.2.2 Inland Wetlands
3.3 Wetland Hydrology
3.4 Wetland Soils
3.4.1 Physical Characteristics
3.4.2 Biochemical Characteristics
3.4.3 Biological Characteristics
3.5 Wetland Vegetation
3.6 Biogeochemical Features of Wetlands
3.6.1 Presence of Molecular Oxygen in Restricted Zones
3.6.2 Sequential Reduction of Other Inorganic Electron Acceptors
3.6.3 Aerobic Soil–Floodwater Interface
3.6.4 Exchanges at the Soil–Water Interface
3.6.5 Presence of Hydrophytic Vegetation
3.7 Types of Wetland/Hydric Soils
3.7.1 Waterlogged Mineral Soils
3.7.2 Organic Soils (Histosols)
3.7.3 Marsh Soils
3.7.4 Paddy Soils
3.7.5 Subaqueous Soils
3.7.6 Hydric Soils
3.8 Summary
Study Questions
Further Readings
Chapter 4 Electrochemical Properties
4.1 Introduction
4.2 Theoretical Relationships
4.2.1 E° vs. log K
4.2.2 pe vs. Eh
4.3 Measurement of Eh
4.4 Eh–pH Relationships
4.5 Buffering of Redox Potential (Poise)
4.6 Measurement of Redox Potentials
4.6.1 Construction of Platinum Electrodes
4.6.2 Standardization of Electrodes
4.6.3 Redox Potentials in Soils
4.7 pH
4.7.1 Soil pH
4.7.2 Floodwater pH
4.7.3 pH Effects
4.8 Redox Couples in Wetlands
4.8.1 Intensity
4.8.2 Capacity
4.9 Redox Gradients in Soils
4.10 Specific Conductance
4.11 Summary
Study Questions
Further Readings
Chapter 5 Carbon
5.1 Introduction
5.2 Major Components of the Carbon Cycle in Wetlands
5.2.1 Plant Biomass Carbon (Net Primary Productivity)
5.2.2 Particulate Organic Matter (Detrital and Soil)
5.2.3 Microbial Biomass Carbon
5.2.4 Dissolved Organic Matter
5.2.5 Gaseous Forms of Carbon
5.3 Organic Matter Accumulation
5.4 Characteristics of Detritus and Soil Organic Matter
5.4.1 NonHumic Substances
5.4.1.1 Carbohydrates
5.4.2 Phenolic Substances
5.4.3 Humic Substances
5.5 Decomposition
5.5.1 Leaching and Fragmentation
5.5.2 Photolysis
5.5.3 Extracellular Enzyme Hydrolysis
5.5.4 Catabolic Activity
5.5.4.1 Aerobic Catabolism
5.5.4.2 Anaerobic Catabolism
5.5.4.3 Aerobic vs. Anaerobic Catabolism
5.6 Organic Matter Turnover
5.6.1 Decomposition Rates
5.7 Regulators of Organic Matter Decomposition
5.7.1 Quality and Quantity of Organic Matter
5.7.2 Microbial Communities and Biomass
5.7.3 Water Table or Soil Aeration Status
5.7.4 Availability of Electron Acceptors with Higher Reduction Potentials
5.7.5 Nutrient Availability
5.7.6 Temperature
5.8 Environmental and Ecological Significance
5.9 Functions of Organic Matter in Soils
5.10 Summary
Study Questions
Further Readings
Chapter 6 Oxygen
6.1 Introduction
6.2 Soil Gases
6.3 Oxygen–H2O Redox Couple
6.3.1 Oxygen Diffusion Rate
6.3.2 Soil Oxygen Content
6.4 Sources of Oxygen
6.5 AerobicAnaerobic Interfaces
6.6 Oxygen Consumption
6.6.1 Oxygen as a Reactant
6.6.2 Oxygen as an Electron Acceptor
6.7 Summary
Study Questions
Further Readings
Chapter 7 Adaptation of Plants to Soil Anaerobiosis
7.1 Introduction
7.2 Distribution of Wetland Plants
7.3 Mechanisms of Flood Tolerance
7.3.1 Metabolic Adaptations
7.3.2 Morphological/Anatomical Adaptations
7.3.2.1 Roots
7.3.2.2 Pneumatophores
7.3.2.3 Lenticels
7.3.2.4 Intercellular Airspaces
7.3.3 Aerenchyma Formation
7.3.4 Intercellular Oxygen Concentration
7.4 Mechanisms of Oxygen Movement in Wetland Plants
7.4.1 Diffusion
7.4.2 Mass Flow
7.5 Oxygen Release by Plants
7.6 Measurement of Radial Oxygen Loss
7.7 Soil Phytotoxic Accumulation Effects on Plant Growth
7.7.1 Greenhouse Gas Emissions: Methane
7.7.2 Greenhouse Gas Emissions: Nitrous Oxide
7.8 Oxidizing Power of Plant Roots
7.8.1 Root Iron Plaque Formation
7.9 Effect of Intensity and Capacity of Soil Reduction on Wetland Plant Functions
7.9.1 Effect of Soil Reduction Intensity
7.9.2 Relationship of Reduction Intensity with Root Porosity and Radial Oxygen Loss
7.9.3 Effect of Soil Reduction Intensity on Nutrient Uptake
7.9.4 Soil Reduction Capacity Effects on Carbon Assimilation and Radial Oxygen Loss
7.10 Summary
Study Questions
Further Readings
Chapter 8 Nitrogen
8.1 Introduction
8.2 Forms of Nitrogen
8.2.1 Inorganic Nitrogen
8.2.2 Organic Nitrogen
8.3 Major Storage Compartments
8.3.1 Plant Biomass Nitrogen
8.3.2 Particulate Organic Nitrogen
8.3.3 Microbial Biomass Nitrogen
8.3.4 Dissolved Organic Nitrogen
8.3.5 Inorganic Forms of Nitrogen
8.3.6 Gaseous Forms of Nitrogen
8.4 Redox Transformations of Nitrogen
8.5 Nitrogen Fixation
8.5.1 Regulators of Dinitrogen Fixation
8.5.2 Nitrogen Fixation Rates
8.6 Nitrogen Assimilation by Vegetation
8.7 Organic Nitrogen Accumulation
8.8 Mineralization of Organic Nitrogen
8.8.1 Chemical Composition of Organic Nitrogen
8.8.2 C:N Ratio Concept
8.8.3 Microbial Degradation of Organic Nitrogen
8.8.4 Regulators of Organic Nitrogen Mineralization
8.9 Ammonia Adsorption–Desorption
8.10 Ammonia Fixation
8.11 Ammonia Volatilization
8.11.1 Physicochemical Reaction
8.11.2 Regulators of Ammonia Volatilization
8.12 Aerobic Ammonia Oxidation
8.12.1 Chemoautotrophic Prokaryotes
8.12.2 MethaneOxidizing Bacteria
8.12.3 Heterotrophic Bacteria and Fungi
8.12.4 Regulators of Ammonium Oxidation
8.13 Anaerobic Ammonium Oxidation
8.13.1 Other Processes of Anaerobic Ammonium Oxidation
8.14 Nitrate Reduction
8.14.1 Denitrification
8.14.2 Nitrifier Denitrification
8.14.3 Aerobic Denitrification
8.14.4 Chemodenitrification
8.14.5 Dissimilatory Nitrate Reduction to Ammonia
8.14.6 Regulators of Nitrate Reduction
8.14.7 Nitrate Reduction Rates in Wetlands and Aquatic Systems
8.15 Nitrogen Processing by Wetlands
8.15.1 Ammonium Flux
8.15.2 Nitrate Flux
8.16 Environmental and Ecological Significance
8.17 Summary
Study Questions
Further Readings
Chapter 9 Phosphorus
9.1 Introduction
9.2 Phosphorus Accumulation in Soils
9.2.1 Why Does Phosphorus Added to Wetlands Accumulate in Soils?
9.3 Phosphorus Forms in the Water Column and Soil
9.3.1 Phosphorus Speciation
9.3.2 Water Column
9.3.2 Soil
9.4 Inorganic Phosphorus
9.5 Phosphorus Sorption by Soils
9.5.1 Adsorption–Desorption
9.5.1.1 Isotherm Concepts
9.5.2 Phosphorus Sorption Isotherms
9.5.2.1 Linear Equation
9.5.2.2 Freundlich Equation
9.5.2.3 Langmuir Equation
9.5.2.4 SinglePoint Isotherm
9.5.2.5 Quantity (Q)/Intensity (I) Relationships
9.5.3 Precipitation and Dissolution
9.5.4 Regulators of Phosphorus Retention and Release
9.6 Organic Phosphorus
9.6.1 Forms of Organic Phosphorus
9.6.2 Chemical Characterization of Organic Phosphorus
9.7 Phosphorus Uptake and Storage in Biotic Communities
9.7.1 Microorganisms
9.7.2 Periphyton
9.7.3 Vegetation
9.8 Mineralization of Organic Phosphorus
9.8.1 Abiotic Degradation and Stabilization of Organic Phosphorus
9.8.1.1 Leaching of Soluble Organic Phosphorus
9.8.1.2 Noncatalyzed Hydrolysis of Phosphate Esters
9.8.1.3 Photolysis
9.8.1.4 Stabilization of Organic Phosphorus
9.8.2 Enzymatic Hydrolysis of Organic Phosphorus
9.8.2.1 Phosphatases or Monoesterases
9.8.2.2 Phosphodiesterases
9.8.3 Microbial Activities and Phosphorus Release
9.8.4 Regulators of Organic Phosphorus Mineralization
9.9 Biotic and Abiotic Interactions on Phosphorus Mobilization
9.9.1 Phosphorus–Iron–Sulfur Interactions
9.9.2 Periphyton–Phosphate Interactions
9.9.3 Biotic and Abiotic Interactions of Fe and Ca with Phosphorus
9.9.4 Gaseous Loss of Phosphorus
9.10 Phosphorus Exchange between Soil and Overlying Water Column
9.11 Phosphorus Memory by Soils and Sediments
9.12 Summary
Study Questions
Further Readings
Chapter 10 Iron and Manganese
10.1 Introduction
10.2 Storage and Distribution
10.3 Eh–pH Relationships
10.3.1 Iron
10.3.2 Manganese
10.4 Reduction of Iron and Manganese
10.4.1 Microbial Communities
10.4.2 Biotic and Abiotic Reduction
10.4.2.1 Biotic Reduction
10.4.2.2 Abiotic Reduction
10.4.3 Forms of Iron and Manganese
10.4.3.1 Iron
10.4.3.2 Manganese
10.4.3.3 Complexation of Iron and Manganese with Dissolved Organic Matter
10.4.3.4 Mobile and Immobile Pools of Iron and Manganese
10.5 Oxidation of Iron and Manganese
10.5.1 Microbial Communities
10.5.2 Biotic and Abiotic Oxidation
10.5.2.1 Iron
10.5.2.2 Manganese
10.6 Mobility of Iron and Manganese
10.7 Ecological Significance
10.7.1 Nutrient Regeneration/Immobilization
10.7.1.1 Organic Matter Decomposition and Nutrient Release
10.7.1.2 Phosphorus Release or Retention
10.7.1.3 Coprecipitation of Trace Elements with Iron and Manganese Oxides
10.7.1.4 Siderophores and Complexation of Iron and Manganese Oxides
10.7.2 Ferromanganese Nodules
10.7.3 Root Plaque Formation
10.7.4 Wetting and Drying: Hydrologic Fluctuations
10.7.5 Ferrolysis
10.7.6 Methane Emissions
10.8 Summary
Study Questions
Further Readings
Chapter 11 Sulfur
11.1 Introduction
11.2 Major Storage Compartments
11.3 Forms of Sulfur
11.4 Oxidation–Reduction of Sulfur
11.5 Assimilatory Sulfate and Elemental Sulfur Reduction
11.6 Mineralization of Organic Sulfur
11.7 Electron Acceptor–Reduction of Inorganic Sulfur
11.7.1 Dissimilatory Sulfate Reduction
11.7.2 Role of Sulfur in Energy Flow
11.7.3 Measurement of Sulfate Reduction in Wetland Soils
11.7.4 Regulators of Sulfate Reductions
11.8 Sulfide Toxicity
11.9 Electron Donor–Oxidation of Sulfur Compounds
11.10 Biogenic Emission of Reduced Sulfur Gases
11.11 Sulfur–Metal Interactions
11.12 Exchange between Soil and Water Column
11.13 Sulfur Sinks
11.14 Environmental and Ecological Significance
11.15 Summary
Study Questions
Further Readings
Chapter 12 Metals/Metalloids
12.1 Introduction
12.2 Biogeochemical Regulators of Metal Availability and Transformation
12.2.1 Sorption and Precipitation
12.2.2 Interaction with Organic Matter
12.2.3 Interaction with Clay Minerals
12.2.4 Biotic Transformations
12.2.5 Redox Potential and pH of Soils and Sediments
12.3 Mercury–Methyl Mercury
12.4 Arsenic
12.5 Copper
12.6 Zinc
12.7 Selenium
12.8 Chromium
12.9 Cadmium
12.10 Lead
12.11 Nickel
12.12 Summary
Study Questions
Further Readings
Chapter 13 Toxic Organic Compounds
13.1 Introduction
13.2 Abiotic Pathways
13.2.1 Redox Potential–pH
13.2.2 Hydrolysis
13.2.3 Sorption to Suspended Solids and the Substrate Bed
13.2.3.1 Effect of Colloidal Organic Matter in Surface Water on Sorption in Wetlands
13.2.4 Photolysis
13.3 Biotic Pathways
13.3.1 Acclimation
13.3.2 Biodegradation
13.3.3 Cometabolism
13.3.4 Microbial Accumulation
13.3.5 Polymerization and Conjugation
13.4 Metabolism of Organic Compounds
13.4.1 Hydrolysis
13.4.2 Oxidation
13.4.2.1 Hydroxylation
13.4.2.2 Dealkylation
13.4.2.3 βOxidation
13.4.2.4 Decarboxylation
13.4.2.5 Cleavage of Ether Linkage
13.4.2.6 Epoxidation
13.4.2.7 Oxidative Coupling
13.4.2.8 Aromatic Ring Cleavage
13.4.2.9 Heterocyclic Ring Cleavage
13.4.2.10 Sulfoxidation
13.5.3 Reduction
13.4.3.1 Reductive Dehalogenation
13.4.4 Synthesis
13.5 Plant and Microbial Uptake
13.6 Transport Processes
13.6.1 Exchange between Soil and Water Column
13.6.2 Settling and Burial of Particulate Contaminants
13.6.3 Volatilization
13.6.4 Runoff and Leaching
13.7 Regulators
13.7.1 Effect of Electron Acceptors on Toxic Organic Degradation
13.7.2 Bacterial Groups
13.7.3 Effect of Soil Redox–pH Conditions on Degradation
13.7.4 Burial
13.8 Summary
Study Questions
Further Readings
Chapter 14 Soil and Floodwater Exchange Processes
14.1 Introduction
14.2 Advective Flux
14.2.1 Advective Flux Processes
14.2.2 Measurement of Advective Flux
14.2.2.1 Seepage Meters
14.2.2.2 Piezometer
14.2.2.3 Salinity/Conductivity
14.2.2.4 Radium/Radon Isotopes
14.2.2.5 Dyes
14.3 Diffusive Flux
14.3.1 Diffusive Flux Processes
14.4 Bioturbation
14.4.1 Macrobenthos Communities
14.4.2 Benthic Invertebrates and Sediment–Water Interactions
14.5 Wind Mixing and Resuspension
14.6 Exchange of Dissolved Solutes Between Soil/Sediment and the Water Column
14.6.1 GradientBased Measurements
14.6.2 Overlying Water Incubations
14.6.2.1 Benthic Chambers
14.6.2.2 Intact Core Flux
14.7 Sediment Transport Processes
14.7.1 Sediment/Organic Matter Accretion in Wetlands
14.7.2 Measurement of Sedimentation or Accretion Rates
14.7.2.1 Filter Pad Traps
14.7.2.2 Artificial Marker Horizons
14.7.2.3 Sedimentation–Erosion Table
14.7.2.4 Beryllium7 Dating
14.7.2.5 Lead210 Dating
14.7.2.6 Cesium137 Dating
14.7.2.7 Carbon14 Dating
14.7.2.8 Application of Sediment Dating
14.8 Vegetative Flux/Detrital Export
14.9 Air–Water Exchange
14.10 Biogeochemical Regulation of Exchange Processes
14.11 Summary
Study Questions
Further Readings
Chapter 15 Coupled Biogeochemical Cycles: An Integrative Approach
15.1 Introduction
15.2 Biotic Communities and Interactions
15.2.1 Microbial Communities
15.2.2 Periphyton
15.2.3 Vegetation
15.3 Coupled Biogeochemical Processes
15.3.1 Carbon
15.3.2 Nitrogen
15.3.3 Phosphorus
15.3.4 Sulfur
15.4 Ecological and Environmental Significance
15.4.1 Wetlands and Climate Change
15.4.2 Wetlands and Sea Level Rise
15.4.3 Wetlands and Water Quality
15.5 Summary
15.6 Future Directions and Perspectives
References
Index
