The Amazon Basin contains the largest and most diverse tropical rainforest in the world. Besides the Andes and the Atlantic Ocean, the rainforest is bounded to the north by the Guiana crystalline shield and to the south by the Brazilian crystalline shield, marked at their edges by cataracts in the rivers and often dominated by grasslands. This book is motivated not just by the Amazon's scientific interest but also by its role in many ecosystem functions critical to life on Earth. These ecosystems are characterized both by their complexity and their interactive, higher-order linkages among both abiotic and biotic components. Within Amazonia, the Western Amazon (west of 65° latitude) is the most pristine and, perhaps, the most complex within the Amazon Basin. This Western Amazon may be broadly divided into non-flooded forests (e.g. terra firme, white sand, palm) and forests flooded with white water (generally referred to as várzea) and with black water (generally referred to as igapó). Here, for the first time, is a book devoted entirely to Western Amazonia, containing chapters by scientists at the forefront of their own areas of expertise. It should be a valuable resource for all future researchers and scholars who venture into Western Amazonia, as it continues to be one of the most beautiful, mysterious, remote and important ecosystems on Earth.

Table of Contents:
List of Contributors xi Prologue xv 1 Introduction 1 Randall W. Myster 1.1 The Amazon 2 1.2 The Western Amazon 6 1.2.1 Case study: Sabalillo Forest Reserve 8 1.2.1.1 White-sand forest and palm forest plot studies 9 1.2.1.2 Black-water flooded forest (igapó) soil and vegetation studies 10 1.2.2 Case study: Area de Conservacion Regional Comunal de Tamshiyacu-Tahuayo 11 1.2.2.1 Plots in terra firme forest and black-water flooded forest (igapó) 11 1.2.2.2 Seed predation studies in terra firme forest and black-water flooded forest (igapó) 13 1.2.3 Case study: Centro de Investigacion de Jenaro Herrera 13 1.2.3.1 Soil sampling in various forest types 14 1.2.3.2 Seed rain sampling in various forest types 15 1.2.4 Case study: Yasuní experimental station 15 1.2.4.1 Yasuní terra firme forest studies 16 1.2.4.2 Yasuní white-water flooded forest (várzea) studies 17 1.3 About this book 19 Acknowledgements 19 References 19 2 A Floristic Assessment of Ecuador’s Amazon Tree Flora 27 Juan E. Guevara, Hugo Mogollón, Nigel C. A. Pitman, Carlos Ceron, Walter A. Palacios, and David A. Neill 2.1 Introduction 27 2.2 Methods 28 2.3 Study area 29 2.3.1 Yasuní 29 2.3.2 Cuyabeno 29 2.4 Herbarium collections 30 2.5 Floristic inventories 30 2.6 Data analysis 31 2.6.1 Estimation of observed and expected tree species richness 32 2.7 Results 32 2.7.1 Observed patterns of tree species richness 32 2.7.2 Estimated number of tree species in Ecuadorian Amazonia 34 2.7.3 Floristic relationships and discontinuities at local and regional scales 36 2.8 Aguarico-Putumayo watershed 37 2.9 Napo-Curaray basin 37 2.10 Pastaza basin region 38 2.11 Cordillera del Cóndor lowlands 39 2.12 What factors drive gradients in alpha and beta diversity in Ecuador Amazon forests? 41 2.12.1 Climate and latitudinal and longitudinal gradients 41 2.13 The role of geomorphology and soils on the patterns of floristic change in Ecuadorian Amazonia 43 2.14 Potential evolutionary processes determining differences in tree alpha and beta diversity in Ecuadorian Amazonia 44 2.15 Future directions 47 References 48 3 Geographical Context of Western Amazonian Forest Use 53 Risto Kalliola and Sanna Mäki 3.1 Introduction 54 3.2 Conditions set by the physical geography 54 3.3 Pre-Colonial human development 57 3.4 Colonial era 59 3.5 Liberation and forming of nations 63 3.6 World market integration and changing political regimes 64 3.7 Characteristics of the present forest use 67 3.8 Present population and regional integration 73 References 77 4 Forest Structure, Fruit Production and Frugivore Communities in Terra firme and Várzea Forests of the Médio Juruá 85 Joseph E. Hawes and Carlos A. Peres 4.1 Introduction 85 4.2 Methods 88 4.3 Results and discussion 91 4.4 Conclusion 94 References 94 5 Palm Diversity and Abundance in the Colombian Amazon 101 Henrik Balslev, Juan-Carlos Copete, Dennis Pedersen, Rodrigo Bernal, Gloria Galeano, Álvaro Duque, Juan Carlos Berrio, and Mauricio Sanchéz 5.1 Introduction 101 5.2 Study area 102 5.3 Methods 103 5.4 Results 104 5.4.1 Palms in terra firme forests (Figure 5.2) 104 5.4.2 Palms in floodplain and terrace forests (Figure 5.6) 104 5.4.2.1 Growth forms 111 5.4.2.2 Palm architecture 111 5.4.2.3 Palm species richness (Table 5.1) 113 5.4.2.4 Palm diversity 113 5.4.2.5 Palm abundance 113 5.4.2.6 Palm leaf shape 118 5.5 Discussion 118 Acknowledgements 121 References 121 6 Why Rivers Make the Difference: A Review on the Phytogeography of Forested Floodplains in the Amazon Basin 125 Florian Wittmann and Ethan Householder 6.1 Introduction 125 6.2 The geological history of flood-pulsing wetlands in the Amazon Basin 126 6.2.1 Through the Paleogene 126 6.2.2 The Miocene 126 6.2.3 The Quaternary 127 6.3 Floodplain environments: why rivers make the difference 128 6.3.1 Trees and flooding 128 6.3.2 Trees and dispersal in semi-aquatic habitats 130 6.3.3 Trees and alluvial soils 130 6.3.4 Trees, hydro-geomorphic disturbance and light regimes 133 6.3.5 Trees and wetland microclimates 135 6.4 Conclusions 135 References 136 7 A Diversity of Biogeographies in an Extreme Amazonian Wetland Habitat 145 Ethan Householder, John Janovec, Mathias W. Tobler, and Florian Wittmann 7.1 Introduction 145 7.2 Methods 147 7.2.1 Habitat description 147 7.2.2 Vegetation sampling 147 7.3 Construction of a biogeographic framework 149 7.4 Results 150 7.5 Discussion 150 7.5.1 Insights into local assemblies 152 7.5.2 Insights into biogeographic processes 153 7.5.3 Limits of the data 154 Acknowledgements 154 References 155 8 Forest Composition and Spatial Patterns across a Western Amazonian River Basin: The Influence of Plant–Animal Interactions 159 Varun Swamy 8.1 Introduction 159 8.2 Methods 162 8.2.1 Site description and history 162 8.2.2 Study design 164 8.3 Analysis 165 8.3.1 Compositional patterns 165 8.3.2 Spatial patterns 165 8.3.2.1 Intra-cohort spatial patterns 165 8.3.2.2 Inter-cohort spatial patterns 166 8.4 Results 166 8.4.1 Compositional patterns 166 8.4.2 Spatial patterns 171 8.4.2.1 Intra-cohort spatial patterns 171 8.4.3 Inter-cohort spatial patterns 172 8.5 Discussion 173 References 177 9 Bird Assemblages in the Terra Firme Forest at Yasuní National Park 181 Andrés Iglesias-Balarezo, Gabriela Toscano-Montero, and Tjitte de Vries 9.1 Introduction 181 9.2 Methods 182 9.3 Results and discussion 183 References 191 10 Conclusions, Synthesis and Future Directions 195 Randall W. Myster 10.1 Conclusions 195 10.2 Synthesis 198 10.3 Future directions 200 References 201 Index 203