1;Contents;4 2;List of Contributors;8 3;Introduction;12 4;Part I The Physical and Chemical Environment;16 4.1;1 Physical Geography of the Basin;17 4.1.1;1.1 Introduction;17 4.1.2;1.2 Geology;17 4.1.3;1.3 Climate;19 4.1.4;1.4 Hydrography;22 4.1.5;References;41 4.2;2 Geomorphology;42 4.2.1;2.1 The Surrounding Regions;42 4.2.2;2.2 Neotectonics;47 4.2.3;2.3 Climate;48 4.2.4;2.4 Climatic Changes in the Quaternary;48 4.2.5;2.5 The Sediments;49 4.2.6;2.6 Geomorphology;49 4.2.7;References;60 4.3;3 Origin, Evolution, and Types of Floodplain Water Bodies;62 4.3.1;3.1 Introduction;62 4.3.2;3.2 The Middle Paraná Floodplain;62 4.3.3;3.3 Origin and Shape of Lentic Water Bodies;73 4.3.4;3.4 Lake Morphometry;77 4.3.5;3.5 Lake Evolution;84 4.3.6;3.6 Aquatic and Riparian Vegetation as a Morphological Factor;85 4.3.7;3.7 Concluding Remarks;86 4.3.8;References;89 4.4;4 The Physical Dynamics of the River-Lake Floodplain System;91 4.4.1;4.1 Introduction;91 4.4.2;4.2 Water Regime of the Floodplain Lakes;91 4.4.3;4.3 Suspended Sediments;103 4.4.4;4.4 Bottom Sediment Resuspension, Mixing Depth, and Sedimentation Rate;108 4.4.5;4.5 Water Temperature;110 4.4.6;4.6 Lake Heat Content;120 4.4.7;4.7 Work of the Wind and Stability of Stratification;122 4.4.8;4.8 Conclusions;124 4.4.9;References;127 4.5;5 Fluvial Sediments: Main Channel and Floodplain Interrelationships;131 4.5.1;5.1 Introduction;131 4.5.2;5.2 Basic Concepts;132 4.5.3;5.3 The Main Channel;132 4.5.4;5.4 Sediment Transport and Processes in the Alluvial Plain;142 4.5.5;5.5 Conclusions;148 4.5.6;References;149 4.6;6 The Geochemistry of the Paraná River: An Overview;151 4.6.1;6.1 Introduction;151 4.6.2;6.2 Geological and Hydrological Framework;152 4.6.3;6.3 The Chemistry of Dissolved Components;156 4.6.4;6.4 The Signature of Weathering in the Drainage Basin;161 4.6.5;6.5 The Provenance of Sediments;167 4.6.6;6.6 Main Biogeochemical Characteristics;173 4.6.7;6.7 Conclusions;178 4.6.8;References;179 5;Part II Plant Life;183 5.1;7 Phytoplankton;184 5.1.1;7.1 Introduction;184 5.1.2;7.2 Phytoplankton Distribution Along the Main River and at Cross Channel;185 5.1.3;7.3 Temporary Variations during Normal Hydrological Cycles and Extraordinary Periods in the Main Channel;189 5.1.4;7.4 Temporary Changes in Side Channels of Different Size and Connectivity Degree;191 5.1.5;7.5 Temporary Variations in Floodplain Lakes with Different Water Residence Time and Vegetation;196 5.1.6;7.6 Conclusions;207 5.1.7;References;209 5.2;8 Aquatic Macrophytes;211 5.2.1;8.1 Introduction;211 5.2.2;8.2 Plant Communities and Succession;213 5.2.3;8.3 Habitat Characteristics and Ecological Factors;218 5.2.4;8.4 Plant Dynamics and Growth;224 5.2.5;8.5 Biomass and Productivity;225 5.2.6;8.6 Use of Resources;228 5.2.7;8.7 Conclusions;229 5.2.8;References;230 6;Part III Invertebrate Animal Life;233 6.1;9 Zooplankton;234 6.1.1;9.1 Introduction;234 6.1.2;9.2 Zooplankton of Rivers and Floodplain Shallow Lakes: Similarities and Differences;235 6.1.3;9.3 Factors Regulating Zooplankton Abundance and Seasonal Distribution in Floodplain Lakes;238 6.1.4;9.4 Flood Pulse, Physical Variables and Potamozooplankton Dynamics;241 6.1.5;9.5 Zooplankton of the Main Channel and the Contribution of High Reaches and the Floodplain;245 6.1.6;9. 6 Connectivity and Species Richness;247 6.1.7;9.7 Conclusions;249 6.1.8;References;250 6.2;10 Benthic Invertebrates;255 6.2.1;10.1 Introduction;255 6.2.2;10.2 Spatiotemporal Longitudinal Patterns;257 6.2.3;10.3 Spatiotemporal Lateral and Vertical Patterns;264 6.2.4;10.4 Temporary Marginal Wetlands;265 6.2.5;10.5 Floodplain Lakes;266 6.2.6;10.6 Vertical Dimension;268 6.2.7;10.7 Factors Influencing the Benthic Structure;269 6.2.8;10.8 Functional Feeding Groups and Food Webs;270 6.2.9;10.9 Bivalvia Invasive Species in Benthic Communities;272 6.2.10;10.10 Conclusions;273 6.2.11;References;275 6.3;11 Littoral Communities. Macrocrustaceans;280 6.3.1;11.1 Introduction;280 6.3.2;11.2 Biological Features;282 6.3.3;11.3 Intra-