As pressures on Australia's inland waters intensify from population growth, expanding resource development and climate change, there is an urgent need to manage and protect these special areas. Understanding their ecology underpins their wise management and conservation.

Australian Freshwater Ecology vividly describes the physical, chemical and biological features of wetlands, lakes, streams, rivers and groundwaters in Australia. It presents the principles of aquatic ecology linked to practical management and conservation, and explains the causes, mechanisms, effects and management of serious environmental problems such as altered water regimes, eutrophication, salinization, acidification and sedimentation of inland waters.

Key features:

• contributions from a diverse, highly qualified team of aquatic ecologists whose expertise spans the ecology and management of standing and running waters in Australia
• sections covering groundwaters, biodiversity, temporary and tropical waters, climate change, invasive species and freshwater conservation
• numerous Australian case-studies and guest 'text-boxes' showing management in practice
• concise descriptions of ecological processes and conceptual models illustrated with original, high- quality diagrams and photographs

Readable and logically structured, this text supports undergraduate and postgraduate courses in aquatic ecology and management. It is a valuable reference for consultants, restoration ecologists, water resource managers, science teachers, and other professionals with an interest in the ecology of surface and groundwaters.

Andrew J. Boulton, University of New England, Armidale, Australia

Margaret A. Brock, University of Tasmania, Tasmania, Australia

Belinda J. Robson, Murdoch University, Murdoch, Australia

Darren S. Ryder, University of New England, Armidale, Australia

Jane M. Chambers, Murdoch University, Murdoch, Australia

Jenny A. Davis, University of Canberra, Canberra, Australia

About this book, xi

About the companion website, xii

PART I: PROCESSES IN AQUATIC ECOSYSTEMS, 1

1 Australian waters: diverse, variable and valuable, 3

1.1 The challenge for aquatic ecologists, 3

1.2 Defi ning some common terms, 6

1.3 Australian inland waters: their diversity and distribution, 6

1.4 The water regime: 'where, when and to what extent water is present', 7

1.4.1 Water budgets, scale issues and human influences on water regimes, 7

1.4.2 Components of the water regime, 8

1.4.3 Water regime variability, 9

1.5 Linkages in aquatic ecosystems: from molecular bonds to global exchanges, 11

1.5.1 Wonderful water and its molecular linkages, 11

1.5.2 Linkages at the catchment scale, 12

1.5.3 Linkages at the global scale: the hydrological cycle, 13

1.5.4 Continental linkages and surface waters in Australia, 15

1.5.5 Continental linkages and groundwaters in Australia, 19

1.6 The structure of this book, 20

2 Physical processes in standing waters, 21

2.1 Depth and physical processes, 21

2.2 Let there be light ..., 21

2.2.1 Light reaching the water surface, 21

2.2.2 Light below the water surface, 22

2.2.3 Seeing through water: Secchi discs and quantum sensors, 24

2.3 The euphotic zone, 24

2.4 Light and life, 25

2.5 Temperature and stratification, 25

2.5.1 Causes of stratifi cation, 26

2.6 Using circulation patterns to classify standing waters, 27

2.7 Ecological implications of the different types of stratifi cation and mixing, 29

2.8 Deep versus shallow standing waters: depth matters, 31

2.8.1 How deep standing waters form, 32

2.8.2 How shallow standing waters form, 32

2.9 Synthesis, 35

3 Chemical processes in standing waters, 37

3.1 'There's a certain chemistry ...', 37

3.2 Dissolved gases, 37

3.2.1 Oxygen, 38

3.2.2 Carbon dioxide, 41

3.2.3 Hydrogen, 42

3.2.4 Methane, 43

3.3 Sources of ions, 45

3.4 Ionic composition of Australian standing waters, 45

3.5 Conductivity, salinity and total dissolved solids, 45

3.6 Ionic composition and trophic state, 47

3.6.1 Some common anions, 47

3.6.2 Some common cations, 48

3.7 Redox reactions and redox potential, 50

3.8 Redox reactions and some common metals, 51

3.9 Nutrients, nutrient limitation and ecological stoichiometry, 52

3.9.1 Phosphorus, 53

3.9.2 Nitrogen, 55

3.9.3 Carbon, 58

3.10 Water regime, drying and water chemistry, 60

3.10.1 What happens to water chemistry during a wetting-drying cycle?, 60

3.11 Synthesis, 62

4 Biological processes in standing waters, 63

4.1 Biological players on a physical and chemical stage, 63

4.2 Major ecological zones and habitats, 64

4.3 Blurred boundaries and mobile assemblages, 66

4.4 Trophic groups and sources of energy, 66

4.5 Producers, 69

4.5.1 An ecological classification of producers, 72

4.5.2 Microscopic aquatic plants, 72

4.5.3 Macroscopic aquatic plants, 74

4.5.4 Plants living in water: benefits and constraints, 76

4.5.5 Alternative states: changes in plant dominance in shallow waterbodies, 77

4.6 Consumers, 80

4.6.1 Decomposers: the importance of microbes and fungi, 80

4.6.2 Invertebrate detritivores, 81

4.6.3 Invertebrate herbivores, 82

4.6.4 Invertebrate carnivores, 83

4.6.5 Vertebrate herbivores, 84

4.6.6 Vertebrate carnivores, 85

4.6.7 Predation and trophic cascades, 86

4.6.8 Trophic cascades and biomanipulation, 87

4.6.9 How vertebrates use waterbodies: linkages and subsidies, 87

4.7 Biological processes in temporary standing waters, 90

4.8 Biological processes in saline standing waters, 94

4.9 Synthesis, 95

5 Physical processes in running waters, 97

5.1 Flow and the diversity of running waters, 97

5.2 Scale, ecological hierarchies and networks, 97

5.3 A hierarchical classification of physical features, 99

5.3.1 Physical features and channel flows, 101

5.4 Hydrology and stream flow, 103

5.4.1 Measuring discharge, 103

5.4.2 Measuring current velocity, 104

5.5 Hydrographs, catchment characteristics and groundwater interactions, 106

5.6 Flow variability and its implications, 108

5.7 The physical process of transport, 110

5.7.1 The sources of sediment, 111

5.7.2 Sediment particle size and distribution, 112

5.7.3 Current velocity, erosion and transport, 113

5.7.4 Sediment dynamics and channel form, 114

5.7.5 Floodplain sedimentation and billabong formation, 115

5.8 River profi les and longitudinal changes in physical features, 118

5.9 Synthesis, 119

6 Chemical processes in running waters, 120

6.1 The complex web of factors, 120

6.2 Dissolved gases, 120

6.3 Ionic composition of Australian rivers, 123

6.4 Sources of ions, 124

6.5 Nutrients and nutrient spiralling, 126

6.5.1 Transport and retention of nutrients, 128

6.6 Carbon and organic matter, 129

6.6.1 Dissolved organic matter in rivers, 130

6.6.2 Solute processes: dissolved substances in running waters, 132

6.7 Longitudinal changes in chemical features, 133

6.8 Synthesis, 135

7 Biological processes in running waters, 136

7.1 Factors affecting biological processes at various scales, 136

7.2 Zones and habitats: parallels and cont…