xxiii
11.7.3 Early US Defi nition: Circular 39 Defi nition ...... 193
11.7.4 US Fish and Wildlife Service Defi nition ............ 193
11.7.5
Canadian Defi nitions of Wetland ....................... 194
11.7.6
Defi nition of US National
Academy of Sciences ......................................... 194
11.7.7 An International Defi nition of Wetland .............. 195
11.7.8 Legal Defi nitions ................................................ 195
11.7.9
Defi nition of US Army Corps of Engineers ....... 195
11.7.10 Food Security Act Defi nition ............................. 195
11.7.11 Choice of a Wetland Defi nition .......................... 195
11.7.12 Jurisdictional Wetlands ....................................... 196
11.8 Origin and Evolution of Wetlands ...................................... 196
Suggested Readings ........................................................................ 198
12 Historical Records (Palaeolimnology) ......................................... 199
12.1 Dating of Sediments ........................................................... 199
12.2 Inorganic Chemistry ........................................................... 200
12.3 Organic Constituents .......................................................... 202
12.4 Pigments ............................................................................. 202
12.5 Morphological Remains ..................................................... 203
12.5.1
Pollen .................................................................. 203
12.5.2 Algal Remains .................................................... 204
12.6 Plant Macrofossils .............................................................. 204
12.7 Animal Remains ................................................................. 204
Suggested Readings ........................................................................ 205
13 Wetland Biogeochemistry ............................................................. 207
13.1 Chemical Transformations in Wetlands ............................. 208
13.1.1 Oxygen and Redox Potential .............................. 208
13.2 Nitrogen Transformations .................................................. 208
13.3 Iron and Manganese Transformations ................................ 208
13.4 Sulphur Transformations .................................................... 209
13.4.1
Sulphide Toxicity ............................................... 209
13.5 Carbon Transformations ..................................................... 209
13.6 Phosphorus Transformations .............................................. 209
13.7 Chemical Transport into Wetlands ..................................... 210
13.8 Chemical Mass Balances of Wetlands ................................ 211
13.9 Wetland pH ......................................................................... 211
13.10 Anthropogenic Effects ........................................................ 211
13.11 Inference ............................................................................. 211
Suggested Readings ........................................................................ 213
14 Wetland Hydrology ....................................................................... 215
14.1 The Importance of Hydrology in Wetlands ........................ 215
14.2 Biotic Control of Wetland Hydrology ................................ 216
14.3 Studies on Wetland Hydrology ........................................... 217
14.4 Wetland Hydro-period ........................................................ 217
14.4.1
Year-to-Year Fluctuations ................................... 218
14.4.2 Pulsing Water Levels .......................................... 218
Contents
11.7.3 Early US Defi nition: Circular 39 Defi nition ...... 193
11.7.4 US Fish and Wildlife Service Defi nition ............ 193
11.7.5
Canadian Defi nitions of Wetland ....................... 194
11.7.6
Defi nition of US National
Academy of Sciences ......................................... 194
11.7.7 An International Defi nition of Wetland .............. 195
11.7.8 Legal Defi nitions ................................................ 195
11.7.9
Defi nition of US Army Corps of Engineers ....... 195
11.7.10 Food Security Act Defi nition ............................. 195
11.7.11 Choice of a Wetland Defi nition .......................... 195
11.7.12 Jurisdictional Wetlands ....................................... 196
11.8 Origin and Evolution of Wetlands ...................................... 196
Suggested Readings ........................................................................ 198
12 Historical Records (Palaeolimnology) ......................................... 199
12.1 Dating of Sediments ........................................................... 199
12.2 Inorganic Chemistry ........................................................... 200
12.3 Organic Constituents .......................................................... 202
12.4 Pigments ............................................................................. 202
12.5 Morphological Remains ..................................................... 203
12.5.1
Pollen .................................................................. 203
12.5.2 Algal Remains .................................................... 204
12.6 Plant Macrofossils .............................................................. 204
12.7 Animal Remains ................................................................. 204
Suggested Readings ........................................................................ 205
13 Wetland Biogeochemistry ............................................................. 207
13.1 Chemical Transformations in Wetlands ............................. 208
13.1.1 Oxygen and Redox Potential .............................. 208
13.2 Nitrogen Transformations .................................................. 208
13.3 Iron and Manganese Transformations ................................ 208
13.4 Sulphur Transformations .................................................... 209
13.4.1
Sulphide Toxicity ............................................... 209
13.5 Carbon Transformations ..................................................... 209
13.6 Phosphorus Transformations .............................................. 209
13.7 Chemical Transport into Wetlands ..................................... 210
13.8 Chemical Mass Balances of Wetlands ................................ 211
13.9 Wetland pH ......................................................................... 211
13.10 Anthropogenic Effects ........................................................ 211
13.11 Inference ............................................................................. 211
Suggested Readings ........................................................................ 213
14 Wetland Hydrology ....................................................................... 215
14.1 The Importance of Hydrology in Wetlands ........................ 215
14.2 Biotic Control of Wetland Hydrology ................................ 216
14.3 Studies on Wetland Hydrology ........................................... 217
14.4 Wetland Hydro-period ........................................................ 217
14.4.1
Year-to-Year Fluctuations ................................... 218
14.4.2 Pulsing Water Levels .......................................... 218
Contents