Coastal Wetlands (eBook)

Front Cover 1
Coastal Wetlands: An Integrated Ecosystem Approach 4
Copyright Page 5
Table of Contents 6
Preface 20
List of Contributors 22
List of Reviewers 32
Chapter 1 Coastal Wetlands: A Synthesis 34
1 Introduction 34
2 A Synthesis of Coastal Wetlands Science 35
2.1 Geography 36
2.2 Geomorphology evolution under climate change 37
2.3 The influence of vegetation on the geomorphology evolution with climate change 39
2.4 The stabilizing role of vegetation 42
2.5 State change and coastal evolution 46
2.6 The role of physical disturbances 47
2.7 The role of herbivores 51
2.8 Observations across ecosystem types 54
2.9 The human impact 61
2.10 Modeling and predictions 64
2.11 Coastal wetland ecosystems as a component of estuaries 65
2.12 Coastal wetland socioeconomics 67
2.13 Coastal wetlands are essential for our quality of life 71
3 Lessons from the Chapters in this Book 76
3.1 Coastal wetlands as ecosystems 77
3.2 Physical processes 78
3.3 Tidal flats 80
3.4 Marshes and seagrasses 81
3.5 Mangroves 84
3.6 Coastal wetland restoration and management 86
3.7 Coastal wetland sustainability and landscape dynamics 89
References 90
Part I Coastal Wetlands as Ecosystems 96
Chapter 2 The Morphology and Development of Tropical Coastal Wetlands 98
1 Introduction 98
2 Mangrove and Associated Wetlands 99
3 Sedimentation and the Development of Wetlands 102
4 Sea-Level Controls on Wetland Development 104
5 Sea-Level Change and the Diversification of West Indian Mangroves 107
6 Sea-Level Change and the Evolution of Mangrove Habitats in the IWP 109
7 Impact of Future Climate and Sea-Level Change 113
8 Summary and Concluding Remarks 115
References 116
Chapter 3 Temperate Coastal Wetlands: Morphology, Sediment Processes, and Plant Communities 122
1 Introduction 122
2 Factors Controlling Sediment Dynamics 124
2.1 The "ramp” model of salt marsh accretion 125
2.2 The "creek" model of salt marsh accretion 126
2.3 Storms and salt marsh erosion 127
3 Factors Controlling Patterns of Vegetation 128
3.1 Zonation of vegetation 128
3.2 Ecological development 129
4 Geographic Variation 130
4.1 Northern Europe 130
4.2 Eastern North America 131
4.3 Western North America 136
4.4 Mediterranean 137
4.5 Eastern Asia 137
4.6 Australasia 138
4.7 South America 140
5 Human Impact and Climate Change 141
5.1 Human impact 141
5.2 Climate and sea-level change 143
6 Summary 144
References 145
Chapter 4 Polar Coastal Wetlands: Development, Structure, and Land use 152
1 Introduction 152
2 Geology/Geomorphology 154
3 Oceanography 157
4 Climate 158
5 Structure of Coastal Wetlands 160
6 Vegetation of Polar Coastal Wetlands 166
7 Fauna of Polar Coastal Wetlands 169
7.1 Invertebrate fauna 170
7.2 Vertebrate fauna using coastal wetlands 173
8 Environmental Hazards 180
9 Conclusions and Research Priorities 181
References 182
Part II Physical Processes 190
Chapter 5 Intertidal Eco-Geomorphological Dynamics and Hydrodynamic Circulation 192
1 Introduction 192
2 Intertidal Eco-Geomorphological Evolution 196
2.1 Poisson hydrodynamic model 197
2.2 Model of channel network early development 198
2.3 Model of marsh platform evolution 201
3 Results 204
4 Discussion 210
5 Conclusions 211
Acknowledgments 212
References 212
Chapter 6 Tidal Courses: Classification, Origin, and Functionality 218
1 Introduction 218
2 Proposed Tidal Course Classification 220
3 Geomorphology of Tidal Courses 222
4 Course Networks and Drainage Systems 229
5 Origin of Tidal Courses 231
6 Course Evolution 236
7 Summary 239
Acknowledgments 239
References 239
Chapter 7 Heat Energy Balance in Coastal Wetlands 244
1 Introduction 244
2 Mid-Latitudes 248
3 Low Latitudes 253
4 High Latitudes 255
5 Summary 258
Acknowledgments 259
References 259
Chapter 8 Hydrodynamics and Modeling of Water Flow in Mangrove Areas 264
1 Introduction 264
1.1 Peculiar hydrodynamics in mangrove area 266
1.2 Material dispersion 266
1.3 Holistic system 266
2 Physical Characteristics of Mangrove Topography and Vegetation 266
2.1 Classification of mangrove topography 267
2.2 Bottom condition of mangrove swamps 269
2.3 Influence of the vegetation on the hydrodynamics 269
3 Peculiar Hydrodynamics in Mangrove Areas 273
3.1 General equations that control water flow 273
3.2 Timescales of flow system 274
4 Modeling 278
4.1 Hydraulic model 278
4.2 Material dispersion model 284
4.3 Ecosystem model as the holistic system 288
5 Summary 290
Acknowledgments 291
References 291
Chapter 9 Mathematical Modeling of Tidal Flow over Salt Marshes and Tidal Flats with Applications to the Venice Lagoon 296
1 Introduction 296
2 Wetting and Drying, and the Dynamics of Very Shallow Flows 298
3 Wind and Wind Waves 305
4 Salt Marsh Vegetation 312
5 Salt Marshes and Tidal Flats Morphodynamics 314
6 Conclusions 318
Acknowledgments 319
References 319
Part III Tidal Flats 326
Chapter 10 Geomorphology and Sedimentology of Tidal Flats 328
1 Introduction 328
2 Basic Conditions for the Formation of Tidal Flats 330
3 Zonation in Sedimentation and Flat Surface Morphology 331
3.1 Vertical sediment sequences 331
3.2 Sediment and morphology on intertidal mud flats 333
3.3 Sediment and morphology on mixed sand–mud flats 336
3.4 Sediment and morphology on sand flats 338
4 Factors and Processes 338
4.1 Influences of quantity and composition of sediment supply 338
4.2 Sedimentation during tidal cycles 341
4.3 Long-term accretion–erosion cycles 343
4.4 Tidal creek systems 344
5 Summary 344
Acknowledgments 345
References 345
Chapter 11 Intertidal Flats: Ecosystem Functioning of Soft Sediment Systems 350
1 Introduction 350
2 The Depositional Habitat 352
2.1 The physical background to life in depositional habitats 354
2.2 The functional difference between mud and sand systems 357
3 The Functional Role of Biota 361
3.1 Patterns of life 361
3.2 Effects of sediment disturbance 364
3.3 Biodiversity impacts 366
3.4 Distribution in space and time 367
3.5 Trophic structure 368
3.6 New functional groups? 369
4 Future Shock: Climate Change and Ecosystem Function 370
Acknowledgments 371
References 371
Chapter 12 Biogeochemical Dynamics of Coastal Tidal Flats 378
1 Introduction 378
2 Transport Processes on Intertidal Flats 380
3 Microbial Processes 383
3.1 Organic matter sources 384
4 Nitrogen Cycle 385
4.1 Nitrogen fixation 385
4.2 Nitrification and nitrate reduction 387
4.3 Exchange of dissolved nitrogen between the sediment and the water column 390
4.4 Benthic microalgal N assimilation 391
5 Phosphorus Cycle 392
6 Silicon Cycle 395
7 Concluding Remarks 397
Acknowledgments 398
References 398
Part IV Marshes and Seagrasses 408
Chapter 13 Productivity and Biogeochemical Cycling in Seagrass Ecosystems 410
1 Introduction 410
1.1 Primary productivity 411
1.2 Fate of primary productivity – export and burial 413
2 Sediment Biogeochemistry – Modified by Seagrasses 416
2.1 Microscale effects 424
2.2 Nutrient cycling – importance of root uptake 425
3 Human Pressures and Effects on Biogeochemistry 426
4 Future Perspectives and Conclusions 428
Acknowledgment 429
References 429
Chapter 14 Tidal Salt Marshes: Geomorphology and Sedimentology 436
1 Introduction 436
2 Geographical Distribution 438
3 Why Salt Marshes Exist? 438
4 Geomorphology 439
4.1 Marsh evolution versus inheritance 439
4.2 Marsh edges and coastal change 439
4.3 Marsh terraces 440
4.4 Channels, creeks, and gullies 440
4.5 Creek networks 441
5 Morphodynamics 442
5.1 Tidal regime 442
5.2 Sediment sources and supply 442
5.3 Channelized flows 442
5.4 Platform flows 443
5.5 Accretion, compaction, and sea level change 443
6 Sedimentology 445
6.1 Grain size 445
6.2 Tidal bedding 446
6.3 Lithostratigraphic architecture 449
7 Concluding Discussion 450
References 450
Chapter 15 Ecosystem Structure of Tidal Saline Marshes 458
1 Introduction 458
2 Saline Marsh Communities 459
2.1 Emergent vegetation 459
2.2 Benthic algae 461
2.3 Nekton 461
2.4 Reptiles 462
2.5 Birds 463
2.6 Mammals 463
3 Interaction among Communities 463
3.1 Effects of animals on emergent vegetation distribution 463
3.2 Emergent vegetation as animal habitat 464
3.3 Nursery function 465
3.4 Saline marsh food webs 466
Acknowledgments 471
References 471
Chapter 16 Salt Marsh Biogeochemistry – An Overview 478
1 Introduction 478
2 Carbon 479
2.1 Exchanges 479
2.2 Internal cycling 482
2.3 Burial 488
3 Nitrogen 488
3.1 Exchanges 488
3.2 Internal cycling 495
3.3 Burial 497
4 Iron and Sulfur 498
4.1 Exchanges 498
4.2 Internal cycling 501
4.3 Burial 504
5 Phosphorus 504
5.1 Exchanges 505
5.2 Internal cycling 508
5.3 Burial 510
6 Marshes in Transition and Directions for Future Work 510
Acknowledgments 511
References 512
Chapter 17 The Role of Freshwater Flows on Salt Marsh Growth and Development 526
1 Introduction 526
2 Freshwater Routes in Salt Marshes 527
2.1 Stream flow 528
2.2 Groundwater flow 530
2.3 Rainfall 532
2.4 Surface flow 533
3 Associated Processes 533
3.1 Nutrient transport 533
3.2 Sediment transport 535
3.3 Organic matter transport 537
3.4 Pollutants 537
3.5 Salinity changes 538
4 Hydrological Impacts in Salt Marshes 540
5 Techniques for the Study of Marsh Hydrology 541
6 Implications of Freshwater Flows for Salt Marsh Management 542
7 Implications of Freshwater Flows for Salt Marsh Creation 542
8 The Ecohydrological Approach in Salt Marsh Studies 544
9 The Way Ahead – Problems and Challenges 545
References 545
Chapter 18 Tidal Freshwater Wetlands 548
1 Introduction 548
2 Hydrogeomorphic Setting 549
3 Biodiversity 552
3.1 Plants 552
3.2 Animals 556
4 Primary Production and Nutrient Cycling 560
5 Threats and Future Prospectus 561
References 563
Chapter 19 Biogeochemistry of Tidal Freshwater Wetlands 568
1 Introduction 568
2 Carbon Biogeochemistry 569
2.1 Carbon inputs 569
2.2 Carbon outputs 571
3 Processes Governing Organic Carbon Metabolism 575
3.1 Anaerobic respiration 576
3.2 Processes regulating methane production, oxidation, and emission 578
4 Nitrogen Biogeochemistry 579
4.1 Nitrogen exchanges 581
4.2 Nitrogen transformations 583
4.3 Nutrient regulation of plant production 584
5 Phosphorus Biogeochemistry 585
6 Silicon Biogeochemistry 587
7 Biogeochemical Effects of Sea-Level Rise 587
8 Concluding Comments 588
Acknowledgments 589
References 589
Part V Mangroves 596
Chapter 20 Geomorphology and Sedimentology of Mangroves 598
1 Introduction 598
2 Mangrove Environmental Settings 599
2.1 Terrigenous settings 599
2.2 Islands 603
2.3 Inland mangroves 603
3 Tidal Range and Sea-Level Control 605
4 Sedimentation in Mangroves 606
4.1 Excessive sedimentation 608
5 Mangroves as Sea-Level Indicators 610
6 Storms/Tsunamis 615
7 Inundation Changes Affecting Mangroves 616
8 Conclusions 618
Acknowledgment 618
References 618
Chapter 21 Geomorphology and Sedimentology of Mangroves and Salt Marshes: The Formation of Geobotanical Units 626
1 Driving Forces Determining Main Morphology and Vegetation Types in the Coastal Zone 626
2 Depositional Environment and Substrate Formation for the Development of Mangroves and Salt Marshes 628
3 Influence of Sea Level and Climate Oscillations on Local Geobotanical Features 630
4 Major Factors Leading to the Development of Salt Marshes and Mangroves at the Amazon Coastal Region: An Integrated Analysis 632
5 Influence of Geomorphology and Inundation Regime of Geobotanical Units on their Sediment Biogeochemistry 633
5.1 Regularly inundated wetlands 634
5.2 Rarely inundated wetlands 637
5.3 Waterlogged wetlands 639
5.4 Salt marshes and mangroves: Nutrient sources or sinks? 640
References 641
Chapter 22 Paradigm Shifts in Mangrove Biology 648
1 Introduction 648
2 Shifts in Established Paradigms 649
2.1 Rates of mangrove net primary productivity rival those of other tropical forests 649
2.2 Mangrove forests appear to be architecturally simple, but factors regulating succession and zonation are complex 655
2.3 Mangrove tree growth is not constant but related to climate patterns 657
2.4 Tree diversity is low, but faunal and microbial diversity can be high 657
2.5 Arboreal communities are important in food webs, exhibiting predatory, symbiotic, and mutualistic relations 659
2.6 Plant–Microbe–Soil Relations are tightly linked and help conserve scarce nutrients 660
2.7 Crabs are keystone species influencing function and structure in many, but not all, mangrove forests 661
2.8 Algae, not just detritus, are a significant food resource 663
2.9 Mangroves are an important link to fisheries 664
2.10 Mangroves are chemically diverse and a good source of natural products 665
3 Conclusions 666
References 667
Chapter 23 Ecogeomorphic Models of Nutrient Biogeochemistry for Mangrove Wetlands 674
1 Introduction 674
2 Ecogeomorphology of Mangroves (Model 1) 681
3 A Multigradient Model (Model 2) 682
4 Geochemical Model (Model 3) 686
4.1 Redox zones in mangrove soils 686
4.2 Transition from reduced to oxidized zones 687
4.3 Hydroperiod effects on transition zones 688
4.4 Lower oxidation zone 689
4.5 Linkages in multigradient and geochemical models 690
5 Soil Biogeochemistry Model (NUMAN, Model 4) 692
6 Mass Balance Exchange (Model 5) 695
6.1 CO2 efflux from mangrove sediments and tidal waters 695
6.2 The balance of N fixation and denitrification 696
6.3 Tidal exchange 704
7 Contrasting Coastal Settings and Biogeochemical Models 705
Acknowledgments 708
References 708
Part VI Coastal Wetland Restoration and Management 718
Chapter 24 Seagrass Restoration 720
1 Introduction 720
2 Regional Activities 722
2.1 Europe 722
2.2 Australia 726
2.3 Oceania 728
2.4 Southeast Asia 729
2.5 China and Japan 730
2.6 New Zealand and the Pacific Islands 731
2.7 United States 732
3 Policy Issues Relevant to Mitigation 734
3.1 Costs of restoration 735
3.2 Valuation of ecosystem services 736
4 Conclusions 737
Acknowledgments 737
References 738
Chapter 25 Tidal Marsh Creation 748
1 Introduction 748
2 Principles and Techniques of Tidal Marsh Creation 749
2.1 Site selection 750
2.2 Conceptual design 750
2.3 Hydrology 751
2.4 Soil 752
2.5 Establishing vegetation 753
3 Evaluating Functional Equivalence of Created Tidal Marshes 756
3.1 Biological productivity and food webs 756
3.2 Biogeochemical cycles 763
4 Summary 766
References 766
Chapter 26 Salt Marsh Restoration 770
1 Introduction 770
2 Setting Objectives 771
3 Planning for the Future 773
4 Addressing Causes and not Symptoms 777
5 Managing Disturbance 778
5.1 Restoring hydrology 778
5.2 Managing weeds 779
5.3 Introduced fauna 782
5.4 Grazing 783
5.5 Pollution 784
6 Conflicting Priorities 787
7 Discussion 788
8 Conclusions 789
References 789
Chapter 27 Managed Realignment: Re-creating Intertidal Habitats on Formerly Reclaimed Land 796
1 Introduction 796
2 Location, Drivers, and Constraints to Managed Realignment 798
3 Site Evolution 801
3.1 Sediments 801
3.2 Creeks 802
3.3 Soils 804
3.4 Nutrient fluxes 805
3.5 Vegetation 806
3.6 Fishes 809
3.7 Spiders 810
3.8 Benthic invertebrates 811
3.9 Birds 812
4 Challenges in Managed Realignment Research 813
Acknowledgments 814
References 814
Chapter 28 Methods and Criteria for Successful Mangrove Forest Restoration 820
1 Introduction 820
2 General Site Selection for Restoration 821
3 Specific Site Selection for Restoration 822
4 Establishing Success Criteria 825
5 Monitoring and Reporting Success 826
6 Functionality of Restored Mangrove Forests 827
7 Summary 829
References 831
Chapter 29 Evaluation of Restored Tidal Freshwater Wetlands 834
1 Introduction 834
2 Characteristics of Restored TFW 835
3 Success Evaluation of Restored Wetlands 838
4 Ecosystem Attributes Measured at Restored TFW 839
5 Criteria for Successful Restoration of TFW 841
5.1 Hydrologic criteria 846
5.2 Geomorphological criteria 846
5.3 Soil criteria 847
5.4 Salinity criteria 848
5.5 Vegetation criteria 848
5.6 Seed bank criteria 849
5.7 Benthic invertebrate criteria 850
5.8 Fish and wildlife criteria 850
6 Case Study: Evaluation of Restored TFW of the Anacostia River, Washington, DC, USA 850
6.1 Characteristics of restored and reference sites 851
6.2 Evaluation of success of restored TFW 852
7 Conclusions and Recommendations 859
7.1 Restoration of TFW in urban landscapes and selection of urban reference sites 859
7.2 Establishment of vegetation 859
7.3 Control of nonnative species 860
7.4 Implications for restoration of TFW 860
Acknowledgements 861
References 861
Part VII Coastal Wetland Sustainability and Landscape Dynamics 866
Chapter 30 Surface Elevation Models 868
1 Introduction 868
2 Measuring Processes that Affect Wetland Elevation 871
3 Types of Models 872
3.1 Zero-dimensional mineral sediment models 873
3.2 Zero-dimensional organic sediment process models 875
3.3 Geomorphic models 879
4 Future Directions for Model Improvement 880
4.1 Data gaps 881
4.2 Integrating models 882
4.3 Improved linkage between sediment models and vegetation 882
4.4 Spatialization 883
5 Conclusions 883
References 883
Chapter 31 Salt Marsh–Mangrove Interactions in Australasia and the Americas 888
1 Introduction 888
2 Distribution/Geomorphic Settings – Where do Mangrove and Salt Marsh Coexist? 889
2.1 Mangrove distribution 889
2.2 Salt marsh distribution 891
2.3 Coexisting mangrove and salt marsh 892
3 Long-Term Dynamics 895
3.1 Tropical northern Australia 895
3.2 Southeastern Australia 896
3.3 Western Atlantic–Caribbean Region 898
4 Recent Interactions 899
4.1 Air photographic evidence of mangrove–salt marsh dynamics in SE Australia 899
4.2 Saltwater intrusion in Northern Australia 900
4.3 Western Atlantic–Gulf of Mexico 900
5 Stressors Controlling Delimitation of Mangrove 902
5.1 Geomorphic and hydrological controls 903
5.2 Climatic controls 906
5.3 Physicochemical factors 907
5.4 Biotic interactions 907
6 Conclusions 908
References 909
Chapter 32 Wetland Landscape Spatial Models 918
1 Introduction 918
2 Physical Models 920
3 Hydraulic Modeling 920
4 Hydrodynamic Modeling 922
4.1 Finite difference solutions 925
4.2 Finite element solutions 926
4.3 Finite volume solutions 927
5 Ecological Models 928
6 Individual-Based Modeling 928
7 Eco-Geomorphological Modeling 929
8 Ecosystem-Level Modeling 930
9 Desktop Dynamic Modeling 933
10 Conclusions 933
Acknowledgments 935
References 935
Subject Index 942
Geographic Index 960
Taxonomic Index 966