Contents......Page 7
1.1 Greenhouse Gases and Reservoirs......Page 48
1.2.1 Water Quality......Page 54
1.2.2 Plankton......Page 57
1.2.3 Benthos......Page 58
1.3 Contents and Rationales......Page 59
Gross Emissions......Page 62
Abstract......Page 63
2.2 History of the Methods Used by Hydro-Québec......Page 64
2.3.1 Floating Chambers with in situ Laboratory Analysis......Page 65
2.3.2 Floating Chambers with ex situ Laboratory Analysis......Page 68
2.3.3 Floating Chambers Coupled to an NDIR or FTIR Instrument......Page 69
2.3.4 Thin Boundary Layer......Page 71
2.4.2 Effect on the Mode of Transportation of the Samples......Page 73
2.4.4 Quality Control for all Methods......Page 74
2.4.5 Comparison of the two Methods with Syring......Page 78
2.4.6 Comparison of Syringe and Thin Boundary Layer Methods......Page 79
2.4.7 Comparison of Syringe and Automated Instrument Methods......Page 80
2.4.8 Comparison of NDIR and FTIR Instruments......Page 81
2.4.9 Advantages and Disadvantages for Each Method......Page 83
2.5 Conclusion......Page 86
Abstract......Page 87
3.1 Introduction......Page 88
3.2.1 Choice of the Gradient Technique for Flux Estimates......Page 89
3.2.2 Assessing Average CO[sub(2)] and CH[sub(4)] Concentration Gradients......Page 90
3.2.3 Assessing Average GHG fluxes......Page 91
3.3.1 Description of the Optical Paths......Page 92
3.3.2 Spectral Resolution of the Laser Device......Page 94
3.3.3 Description of the Signal Detection......Page 95
3.4.1 Technical Developments and Optimizations......Page 97
3.4.2 CO[sub(2)] and CH[sub(4)] Fluxes at FLUDEX - ELA Experimental Reservoir......Page 98
3.4.3 CO[sub(2)] and CH[sub(4)] Fluxes at Robert-Bourassa Hydroelectric Reservoir......Page 105
3.4.4 Major Benefits of Flux Measurements by Tunable Diode Lasers......Page 109
3.5 Conclusion and Directions for Future Work......Page 110
Abstract......Page 112
4.1 Introduction......Page 113
4.2 Net Ecosystem Exchange of CO[sub(2)] (NEE) in Forests......Page 114
4.3 Net Ecosystem Exchange of CO[sub(2)] in Wetlands......Page 122
4.4 CH[sub(4)] Fluxes in Wetlands......Page 126
4.5 CH[sub(4)] Fluxes in Forests......Page 138
4.6 N[sub(2)]O Fluxes in Forest and Wetland Soils......Page 141
4.8 GHG Budgets in Forests and Wetlands......Page 145
4.9 General Evaluation of Gas Flux Data......Page 150
Abstract......Page 153
5.1 Introduction......Page 154
5.2 Lakes and Reservoirs Sampled in this Study......Page 157
5.2.1 Sediment Sampling for Gases......Page 159
5.2.2 Diffuse Flux Calculations......Page 162
5.3.1 Sediment Gas Diffuse Flux......Page 166
5.3.2 Relationships Between Sediment Gas Fluxes and Lake and Reservoir Trophic Conditions......Page 170
Acknowledgements......Page 176
Abstract......Page 178
6.1 Introduction......Page 179
6.2 Soil Organic Carbon Density......Page 180
6.3 Physical and Biological Factors Affecting SOC Density......Page 188
6.4 Uncertainties of SOC Estimates......Page 192
6.5 Organic Carbon in Vegetation......Page 193
6.6 High Spatial Heterogeneity of Biomass......Page 196
6.7 Uncertainties in Evaluating the Organic Carbon in Vegetation......Page 201
6.8 Total Carbon Densities and Stocks of Forest Biomes......Page 204
6.9 Export of Organic Carbon to Aquatic Ecosystems......Page 206
6.10 Conclusion......Page 208
Abstract......Page 209
7.2 Estuaries: Some Useful Definitions for Describing Carbon Cycling and Gas Emissions......Page 210
7.3 Organic Carbon Sources and Mineralization in Estuaries......Page 212
7.4 Estuarine Specificity for Gas Transfer......Page 213
7.5 Carbon Dioxide Emissions......Page 216
7.6 Methane Emissions......Page 222
7.7 Significance at the Global Scale......Page 228
Acknowledgments......Page 229
8.1 Introduction......Page 230
8.2.1 Study Areas......Page 231
8.2.2 Measurement of GHG Fluxes and Other Variables......Page 233
8.3.1 Spatial Variation of GHG Emissions......Page 239
8.3.2 Temporal Variation of GHG Emission from Reservoirs......Page 250
8.4 Conclusion......Page 252
9.1 Introduction......Page 254
9.2.1 Study Areas......Page 255
9.2.3 General Chemical Characteristics of the Water Bodies......Page 260
9.3 Results and Discussion......Page 264
9.4 Conclusion......Page 271
10.1 Introduction......Page 272
10.2.1 The model......Page 274
10.3.1 ELARP......Page 278
10.3.2 FLUDEX......Page 280
10.4 Discussion......Page 282
10.5 Conclusions......Page 286
11.1 Introduction......Page 287
11.2.1 Site Description......Page 288
11.3 Methodology......Page 289
11.4 Results and Discussion: Gross Emissions of CO[sub(2)] and CH[sub(4)] from Brazilian Power Dams......Page 291
11.5 Concluding Remarks and Future Orientations......Page 299
11.6.1 Procedures for Capturing Bubbles......Page 301
11.6.2 Calculation of Averages of Greenhouse Gases Emissions by Bubbles......Page 302
11.6.4 Principle of Exchange Rates Measurement......Page 304
Acknowledgements......Page 311
12.1 Introduction......Page 312
12.2.2 Measurements......Page 314
12.3.1 Observed and Predicted Emissions Over 20 Years......Page 316
12.3.3 Long Term Data and Recent Flux Measurements......Page 324
12.4 Conclusion and Perspective......Page 328
12.4.1 Future Initiatives......Page 329
Acknowledgments......Page 331
Processes Leading to GHG Production......Page 332
Abstract......Page 333
13.1 Introduction......Page 334
13.2.1 Field Site and Sample Collection......Page 336
13.2.3 Experimental Conditions......Page 337
13.2.4 Measurements of Carbon Dioxide and Methane......Page 340
13.2.5 Production of Gases......Page 341
13.3.1 Soil Samples......Page 342
13.3.2 Vegetation Samples......Page 346
13.4 Conclusion......Page 354
Acknowledgements......Page 356
14.1 Introduction......Page 357
14.2.1 Study Site......Page 359
14.2.3 In situ Sampling Measurements......Page 361
14.3 Model Construction......Page 363
14.4 Estimation of the FCO[sub(2 prod)]./FCO[sub(2 atm. eq.)] for the Robert-Bourassa Reservoir......Page 364
14.5 Estimating FCO[sub(2 atm. eq)] and Mean CO[sub(2)] Flux at the Air-Water Interface......Page 366
14.6 Estimate of the Mean Annual Diffusive CO[sub(2)] Flux from the Robert-Bourassa Reservoir......Page 370
14.7 Comments and Conclusions......Page 371
Abstract......Page 373
15.1 Introduction......Page 374
15.2.1 Study Site and Reservoir Construction......Page 375
15.2.2 Theoretical Approach to Quantification of Net Reservoir CO[sub(2)] and CH[sub(4)] Production, Gross DIC Production and NPP, and CH[sub(4)] Production and CH[sub(4)] Oxidation......Page 378
15.2.3 Inorganic C and CH[sub(4)] Mass Budgets and Stable Carbon Isotopic Ratio Mass Budgets......Page 380
15.2.4 δ[sup(13)]C Values of Gross DIC Production, NPP, CH[sub(4)] Production and Oxidation......Page 382
15.2.5 Analytical Methods......Page 384
15.3.1 Inorganic C and CH[sub(4)] Budgets and Net Reservoir CO[sub(2)] and CH[sub(4)] Production......Page 385
15.3.2 Gross Reservoir DIC Production and Consumption Via NPP......Page 387
15.3.3 CH[sub(4)] Production and Oxidation......Page 394
15.3.4 Reservoir GHG Production, OC Storage, and Timescale......Page 395
15.3.5 Extrapolation of FLUDEX Results to Other Studies......Page 397
15.4 Conclusions......Page 400
16.1.1 Emission of Greenhouse C Gases......Page 401
16.1.2 Contribution of Soils from Forest Ecosystems......Page 403
16.2 Organic Carbon in Forest Soils......Page 404
16.2.1 Biogeochemical Cycle of Organic Carbon in Forested Ecosystems......Page 405
16.2.2 Key Role of Forest Soils in the Organic Carbon Cycle......Page 408
16.2.3 Nature and Properties of Organic Substances in Soils......Page 410
16.2.4 Functions of Organic Carbon in Soils......Page 414
16.2.5 Links between Carbon and Other Elemental Cycles in Forest Soils......Page 416
16.3.1 Forest Ecosystems from Northeastern North America......Page 423
16.3.3 Forest Ecosystems from Northwestern Europe......Page 431
16.3.4. Carbon Pools and Fluxes in Northern Wetlands......Page 432
16.4.1 Net Role of Soils on the Cycling of Organic Carbon in Terrestrial Ecosystems......Page 435
16.4.2 Changes in the Transport of DOC from Terrestrial to Aquatic Ecosystems......Page 437
17.1 Introduction......Page 439
17.2.1 Long-term Data Set (1978-1984)......Page 441
17.2.2 Recent Data Set......Page 445
17.3.1 Long-term Variation in Zooplankton Community (1978-1984)......Page 446
17.3.2 Relation with Water Quality and Trophic Status......Page 448
17.3.3 Recent Data Set: A Comparison between Reservoirs......Page 450
17.4 Discussion......Page 454
17.5 Conclusions......Page 458
Abstract......Page 459
18.1 Introduction......Page 460
18.2.1 Site Description and Sample Collection......Page 461
18.2.2 Physico-Chemical Variables......Page 462
18.2.3 Bacterial Methane Metabolism......Page 463
18.3.1 Methanogenesis......Page 466
18.3.2 Methanotrophy......Page 472
18.4.1 Methanogenesis......Page 475
18.4.2 Methanotrophy......Page 478
18.5 Methane Biogeochemistry and Concluding Remarks......Page 481
Acknowledgments......Page 483
Abstract......Page 484
19.1 Introduction......Page 485
19.2 Study Sites and Methods......Page 486
19.3.1 Temperature and DOC......Page 488
19.3.2 Bacterial Abundance and Production in the Study Sites......Page 490
19.4.1 Factors Affecting Bacterioplankton Activities (i.e. Production, Specific Production and% HNA)......Page 492
19.4.2 Bacterioplankton Activities and Variations in CO[sub(2)] Fluxes to the Atmosphere......Page 495
19.4.3 Contribution of Bacterioplankton Activities to CO[sub(2)] Fluxes from Freshwaters to the Atmosphere......Page 496
19.5 Conclusion......Page 499
Abstract......Page 500
20.1 Introduction......Page 501
20.2 Study Site......Page 502
20.3 Methods......Page 504
20.4.1 Phytoplankton Biomass......Page 507
20.4.2 Areal Gross Production......Page 509
20.4.3 Areal Planktonic Respiration......Page 510
20.4.4 Spatial Variation of the Production: Respiration Ratio......Page 511
20.4.5 Gross Primary Production and Total Respiration Mass Balance and their Relationship to CO[sub(2)] Flux at the Water-Air Interface......Page 520
Abstract......Page 525
21.2 Ultraviolet Radiation and Dissolved Organic Matter......Page 526
21.2.1 Types of Dissolved Organic Matter......Page 527
21.2.2 Dissolved Organic Matter Quality......Page 528
21.2.3 Photoreactions and DOM......Page 530
21.2.4 Ionic Conditions......Page 534
21.3.1 Plankton......Page 535
21.3.2 Harmful Effects of UV on Microorganisms......Page 537
21.4.1 Vegetation......Page 538
21.4.4 Estimate of the Rate of Photooxidation in Reservoirs......Page 539
21.5 Conclusion......Page 542
22.1 Introduction......Page 544
22.2.1 The Example of the Petit Saut Reservoir and the Downstream River......Page 546
22.2.2 Measurements......Page 548
22.3.1 Stratification and General Water Quality......Page 549
22.3.2 Methane Production and Oxidation in the Reservoir......Page 553
22.3.3 Principal Factors Influencing Water Quality......Page 556
22.4.1 Evidence of a Consumption of Dissolved Oxygen in the Downstream Sinnamary River Due to an Oxidation of Dissolved Methane......Page 559
22.4.2 Building of an Aerating Weir in the Plant Outlet Canal in Order to Guarantee 2 mg L[sup(-1)] of DO in the Downstream Sinnamary River......Page 562
22.4.3 Historical Reconstruction (1994-2002) of the DM Concentrations and Fluxes in the Water Crossing the Dam......Page 563
22.4.4 Efficiency of DM Elimination in the Near Downstream of the Dam (1994-2002)......Page 565
22.4.5 DM Emissions to the Atmosphere in the Sinnamary River Downstream of the Aerating Weir......Page 568
22.4.6 A New Assessment of the Methane Emissions to the Atmosphere in the Downstream Sinnamary River (1994-2002 Period)......Page 571
22.4.8 The Role of DM Oxidation in the DO Budget of the Downstream Sinnamary......Page 572
22.5 General Conclusion......Page 573
Acknowledgements......Page 575
Modelling......Page 576
23.1 Introduction......Page 577
23.2 Methods Used to Estimate Gas Exchange......Page 578
23.3 Discussion of the Methods......Page 580
23.4 Using a Model to Assist Interpretation......Page 582
23.5 Other Sources of Variability......Page 585
23.6 Conclusion......Page 588
24.1 Introduction......Page 589
24.2 Thermodynamic Lake Models......Page 591
24.3.1 Energy Balance Equations......Page 592
24.3.2 Turbulent Diffusion......Page 593
24.3.4 Ice Model......Page 597
24.4 Calculation of CO[sub(2)] and CH[sub(4)] Fluxes at the Air-Water Interface......Page 598
24.4.2 Thin Boundary Layer (TBL)......Page 599
24.5.1 Model Definition of Atmospheric GHG Concentrations and GHG Sources and Sinks......Page 601
24.5.2 Sensitivity Test and Validation......Page 603
24.5.3 Application: Comparison of the Annual CO[sub(2)] Emissions for Two Reservoirs in Central Northern Québec......Page 606
24.6 Conclusion......Page 607
Abstract......Page 610
25.1 Introduction......Page 611
25.2.1 Basic configuration of the reservoir......Page 614
25.2.2 Constitutive equations of the model......Page 617
25.3 Mass transfer of CO[sub(2)] and CH[sub(4)] at the water-air interface......Page 618
25.3.1 Wind effect......Page 619
25.3.3 Mass transfer coefficient for carbon dioxide and methane......Page 620
25.3.4 Effect of ice formation......Page 622
25.3.7 Effect of pH......Page 625
25.3.8 Kinetic parameters......Page 626
25.3.9 Numerical solution of the constitutive equations......Page 629
25.4.1 Input data to the model......Page 631
25.4.2 Simulation with the model......Page 638
25.5.1 Model characteristics......Page 646
25.5.2 Performance of the model......Page 647
Acknowledgements......Page 648
Abstract......Page 649
26.1.1 Terrestrial Ecosystems......Page 650
26.1.2 Aquatic Ecosystems......Page 652
26.1.3 Estuaries......Page 654
26.2 The Issue of Greenhouse Gases in Hydroelectric Reservoirs......Page 656
26.2.1 Flooded Soils and Sediments......Page 657
26.2.2 Water Column......Page 662
26.2.3 Exchange at the Water-Air Interface......Page 663
26.2.4 Reservoir Characteristics......Page 667
26.2.5 Assessment of Net GHG Emissions from Reservoirs......Page 668
26.2.6 Comparison of GHG Emissions from Various Energy Sources......Page 669
26.2.6 Conclusion and Unresolved Issues......Page 671
References......Page 672