Savanna Woody Plants and Large Herbivores

Insights on current research and recent developments in understanding global savanna systems

Increasingly recognized as synonymous with tropical grassy biomes, savannas are found in tropical and sub-tropical climates as well as warm, temperate regions of North America. Savanna Woody Plants and Large Herbivores examines the interactions between woody plants and browsing mammals in global savannas--focusing primarily on the C4 grassy ecosystems with woody components that constitute the majority of global savannas--and discusses contemporary savanna management models and applications.

This much-needed addition to current research examines topics including the varying behavior of browsing mammals, the response to browsing by woody species, and the factors that inhibit forage intake. Contributions from an international team of active researchers and experts compare and contrast different savanna ecosystems, offering a global perspective on savanna functioning, the roles of soil and climate in resource availability and organism interaction, and the possible impacts of climate change across global savannas.

• Fills a gap in literature on savanna management issues, including biodiversity conservation and animal production

• Applies concepts developed in other biomes to future savanna research

• Complements contemporary books on savanna or large herbivore ecology

• Focuses on the woody component of savanna ecosystems and large herbivore interactions in savannas

• Compares tree-mammal systems of savannas and other eco-systems of temperate and boreal regions

• Provides numerous case studies of plant-mammal interactions from various savanna ecosystems

Savanna Woody Plants and Large Herbivores is a valuable addition to those in fields such as ecology, wildlife and conservation biology, natural resource management, and environmental science.

Auteur

PETER FRANK SCOGINGS is Associate Professor, School of Life Sciences, University of KwaZulu-Natal, South Africa. MAHESH SANKARAN is Reader, National Centre for Biological Sciences, India, and Lecturer, Institute of Integrative & Comparative Biology, Faculty of Biological Sciences, University of Leeds, UK.

Contenu
List of Contributors xv

Preface xix

Part I Introduction 1

**1 Distribution and Determinants of Savannas 3
**Sally Archibald, William J. Bond, William Hoffmann, Caroline Lehmann, Carla Staver, and Nicola Stevens

1.1 Introduction 3

1.2 Evolutionary History of Savanna Vegetation and Fauna 4

1.3 Defining Savannas 7

1.3.1 Are Savannas Tropical Systems? 7

1.3.2 Distinguishing Savannas from Grasslands 7

1.3.3 Distinguishing Savannas from Forests 8

1.4 Global Determinants of Savannas 9

1.4.1 Mesic Transition: Points of Contention 10

1.4.1.1 The Role of Nutrients 10

1.4.1.2 Rainfall Seasonality 10

1.4.2 Mesic Transition: Toward Resolution 11

1.4.3 Mesic Transition: Unresolved Ideas 12

1.4.4 Arid Transition 12

1.4.5 Arid Transition: Toward Resolution 13

1.4.6 Determinants of Temperate Savannas 14

1.5 Functional Differences Between Savannas 14

1.5.1 Temperate vs Tropical Savannas 14

1.5.2 Functional Differences Within Tropical Savannas 15

1.6 Conclusions and the Future of Savanna Ecosystems 17

References 17

2 African and Asian Savannas: Comparisons of Vegetation Composition and Drivers of Vegetation **Structure and Function 25
**Jayashree Ratnam, Chintan Sheth, and Mahesh Sankaran

2.1 Introduction 25

2.2 Climate and Vegetation Formations 27

2.3 FineLeaved and BroadLeaved Savannas: Vegetation Structure, Composition, and Geographic Distribution 30

2.4 Role of BottomUp Drivers in Regulating Vegetation Structure: Climate and Soil Nutrients 33

2.5 Role of TopDown Forces: Fire and Herbivory 36

2.6 African and Asian Savannas in the Anthropocene 40

References 42

3 Savannas of Australia and New Guinea: Vegetation and the Functional Role of Extant and Extinct **Fauna 51
**Garry D. Cook, William J. Bond, Edmund C. February, and Richard J. Williams

3.1 Introduction 51

3.2 The Biota of Australia's and New Guinea's Savannas 51

3.3 Climate, Landforms, and Fire 53

3.4 Human History and Impacts 54

3.5 Are Native Mammals Irrelevant? 55

3.6 Was Ecosystem Functioning Different Prior to Human Dispersal to Australia? 57

3.7 Critique of the Nutrient Poverty/Intense Fire Theory 58

3.8 Australia's Lost Megafauna 61

3.9 Habitat Variation and the Pleistocene Megafauna 64

3.10 Impacts of Herbivores in Australian Savannas 64

3.11 Toward a New Hypothesis of PlantAnimal Interactions in Australian Savannas 66

References 67

**4 South American Savannas 77
**Fabian Borghetti, Eduardo Barbosa, Leandro Ribeiro, José Felipe Ribeiro, and Bruno Machado Teles Walter

4.1 Introduction 77

4.2 Origin of South American Savannas 77

4.3 Distribution and Diversity of South American Savannas 78

4.4 Northern Savannas 80

4.4.1 ColomboVenezuelan Llanos 80

4.4.1.1 Orinoco Llanos 80

4.4.1.2 Llanos Orientales 84

4.4.2 Gran Sabana 85

4.4.3 Rio BrancoRupununi Savannas 85

4.4.3.1 Rio Branco Savannas 86

4.4.3.2 Rupununi Savannas 86

4.4.4 Savannas of Amapá 87

4.5 Southern Savannas 87

4.5.1 Savannas of Humaitá 87

4.5.2 Savannas of Pará 87

4.5.3 Beni Savannas 88

4.5.4 Cerrado 89

4.5.4.1 Cerrado (Sensu Stricto) 91

4.5.4.2 Cerrado Park 92

4.5.4.3 Palm Groves 92

4.5.4.4 Vereda 92

4.5.4.5 Campo Limpo (Open Grassland) 92

4.5.4.6 Campo Sujo (Dense Grassland) 92

4.5.4.7 Campo Rupestre (Rocky Field) 96

4.5.5 Pantanal 96

4.5.6 Chaco 97

4.6 Effects of Water Deficit, Herbivory, and Fire on Vegetation Dynamics 102 4.6.1 Water Deficit 1...