An Introduction to Agroforestry: Four Decades of Scientific Developments

Preface
Acknowledgments
Contents
Section I: Introduction
Chapter 1: Historical Developments: The Coming of Age of Agroforestry
1.1 Introduction
1.2 Cultivating Trees and Crops Together: An Age-Old Practice
1.3 Developments in the Agriculture Sector
1.3.1 The Green Revolution
1.3.2 The International Agricultural Research Centers (IARCs)
1.4 Developments in the Forestry Sector
1.4.1 The General Pattern of Forest Resource Utilization Over Time
1.4.2 Major Forestry Research and Development Initiatives Since the 1950s
1.4.3 Deforestation
1.4.4 People-Oriented Forestry Programs
1.5 Formation of ICRAF and the Institutionalization of Agroforestry
References
Chapter 2: Definition and Concepts of Agroforestry
2.1 Introduction
2.2 Evolution of Definitions of Agroforestry
2.3 Definitions Galore
2.4 Concepts, Principles, and Attributes of Agroforestry
2.5 Other Agroforestry-Related Land-Use Systems
References
Chapter 3: Classification of Agroforestry Systems
3.1 Introduction
3.2 Early Efforts in Classification
3.3 Classification Based on the Structure of the System
3.3.1 Nature of Components
3.3.2 Arrangement of Components
3.4 Based on the Function of the System
3.5 Based on Ecological Characteristics
3.6 Based on Socioeconomic Criteria
3.7 Other Approaches to Classification of Tropical Agroforestry Systems
3.8 Agroforestry Systems and Practices
3.9 Classification of Agroforestry Practices in the Temperate Regions
3.10 Concluding remarks: A Framework for Classification of Agroforestry Systems
References
Chapter 4: Global Distribution of Agroforestry Systems
4.1 Introduction
4.2 The Tropical Environment
4.3 Distribution of Tropical Agroforestry Systems
4.3.1 Lowland Humid and Sub-humid Tropics
4.3.2 Semiarid and Arid Tropics
4.3.3 Tropical Highlands
4.4 Agroecological Spread of Tropical Agroforestry Systems
4.5 The Temperate Environment and Land Use Systems
4.6 Temperate Agroforestry Practices
4.7 Temperate vs. Tropical Agroforestry
4.8 Geographical Distribution and Area Under Agroforestry Systems
References
Section II: Agroforestry Systems and Practices
Chapter 5: Shifting Cultivation and Taungya
5.1 Introduction
5.2 Shifting Cultivation
5.2.1 System Overview
5.2.2 The Common Activities in the Practice of Shifting Cultivation
5.2.3 Soil Management Under Shifting Cultivation
5.3 Taungya: An Agroforestry Practice for Forest Plantation Establishment
5.3.1 An Overview of the Taungya Practice
5.3.2 Alternatives/Improvements to Taungya
5.4 Agroforestry Pathways to Improving Shifting Cultivation: Planted Fallows
5.4.1 Fallow Intensification Pathways
5.4.2 Planted Fallows
5.5 Concluding Remarks
References
Chapter 6: Tropical Alley Cropping and Improved Fallows
6.1 Introduction
6.2 Tropical Alley Cropping
6.2.1 Hedgerow Species
6.2.2 Nutrient (Nitrogen) Yield from Tree Species and Soil Fertility
6.2.3 Soil Properties and Soil Conservation
6.2.4 Crop Yields Under Alley Cropping
6.2.5 The Rise and Fall of Alley Cropping
6.3 Improved (Shrub and Tree) Fallows
6.3.1 Improved Fallow: The Practice and Terminology
6.3.2 Improved-Fallow Species
6.3.3 Soil Fertility and Crop Yields Under Improved Fallows
6.3.4 The Rise and Fall of Improved Fallows
6.4 Concluding Remarks
References
Chapter 7: Tropical Homegardens
7.1 Introduction
7.2 Global Distribution of Homegardens
7.3 History, Evolution, and Distribution of Homegardens
7.4 Types of Homegardens
7.5 Ecology and Structure
7.5.1 Floristic Diversity
7.5.2 Vegetation Structure
7.5.3 Ecosystem Services
7.6 Commercialization of Homegardens
7.7 Major Tropical Homegarden Systems
7.7.1 Homegardens of Kerala (India)
7.7.2 Javanese Homegardens of Indonesia
7.7.3 Polynesian Homegardens
7.7.4 The Shamba and Chagga Gardens of East Africa
7.7.5 The Sri Lankan Homegardens
7.7.6 Central American Homegardens
7.7.7 Homegardens in the Brazilian Amazon
7.8 Research on Homegarden Systems
7.9 Concluding Remarks
References
Chapter 8: Shaded Perennial Agroforestry Systems
8.1 Introduction
8.2 Tropical Tree Crops: An Overview
8.2.1 Abundance and Distribution of Species
8.2.2 The Scale of Operations: Commercial Plantations and Smallholder Systems
8.2.3 Research and Development Efforts
8.3 Integrated, Smallholder Land-Use Systems with Shaded Perennial (Plantation) Crops
8.4 Coconut-Based Smallholder Systems: A Notable Example of Integrated Agroforestry
8.4.1 Common Land-Use Features of Coconut-Based Ecosystems
8.4.2 Growth Habits of the Coconut Palm Concerning Multispecies Systems
8.4.3 Intercropping Under Coconuts
8.4.4 Special Forms of Integrated Production Systems with Coconuts
8.4.5 Prospects of Land-Use Intensification with Coconuts
8.5 Shaded Coffee and Cacao Systems
8.5.1 Shaded Coffee Systems
8.5.2 Cacao Production Systems
8.5.3 Shade Trees for Coffee and Cacao
8.6 Other Agroforestry Systems Involving Tropical Tree Crops
8.6.1 Tropical Palms
8.6.2 Multistory Tree Gardens
8.7 Concluding Remarks
References
Chapter 9: Silvopastoral Systems (SPS) in the Tropics and Subtropics
9.1 Introduction
9.2 Tropical and Subtropical SPS: An Introduction
9.3 Common Forms and Terms of Silvopasture
9.4 Common Silvopastoral Grazing Systems in the Drylands
9.4.1 The Parkland System of West Africa
9.4.2 SPS in the Semiarid Brazilian Tropics
9.4.3 SPS in the Arid and Semiarid Parts of India
9.4.4 Other SPS in the Semiarid Regions Worldwide
9.5 The Browsing Systems: Tree Fodder and Fodder Trees
9.5.1 The Cut-and-Carry System
9.5.2 Fodder Banks
9.5.3 Boundary Planting
9.6 Research in Tropical Silvopastoral Systems
9.7 Integrated Crop Livestock Forestry Systems: New Wine in Old Bottles?
9.8 Outlook on Tropical Silvopastoral Systems
References
Chapter 10: Agroforestry Systems in The Temperate Zone
10.1 Introduction
10.2 Historical Perspectives
10.3 Agroforestry Systems in North America
10.3.1 Alley Cropping
10.3.2 Silvopastoral Systems
10.3.3 Windbreak Practices
10.3.4 Riparian and Upland Buffers
10.3.5 Forest Farming
10.4 Agroforestry in Europe
10.4.1 Traditional Practices: The Dehesa System
10.4.2 Traditional Practices: Integrated Fruit-Orchard Agroforestry in Europe
10.4.3 Recent European Initiatives in Agroforestry
10.4.4 Current Status of Agroforestry Systems in Europe
10.5 Agroforestry in Other Temperate/Industrialized Regions
10.5.1 Australia
10.5.2 New Zealand
10.5.3 China
10.5.4 Southern Parts of Latin America
10.6 Concluding Remarks
References
Chapter 11: Other Agroforestry Systems and Practices
11.1 Introduction
11.2 Cinderella Agroforestry Systems
11.3 Agroforestry Systems for Production of Subsidiary Commodities
11.3.1 Fuelwood Trees in AFS
11.3.2 Fodder Trees in AFS
11.3.3 Medicinal and Aromatic Plants in AFS
11.4 Agroforestry for Ecosystem Protection
11.5 Other Agroforestry-Related Land-Use Systems
11.5.1 Social Forestry
11.5.2 Farm Forestry
11.5.3 Community Forestry
11.5.4 Urban Forestry and Urban Food Forestry
11.5.5 Permaculture
11.5.6 Trees Outside Forests
11.5.7 Carbon Farming
11.5.8 Satoyama: The Socio-Ecological Production Landscape of Japan
11.5.9 The Damar Agroforests of Indonesia
11.6 Concluding Remarks
References
Section III: Biophysical Foundations of Agroforestry: Plant Productivity
Chapter 12: General Principles of Plant Productivity
12.1 Introduction
12.2 Photosynthesis and Respiration: The Basics
12.3 Plant and Ecosystem Productivity
12.3.1 Plant Productivity
12.3.2 Ecosystems and Their Productivity
12.3.3 Productivity Measurements and Evaluation in Agroecosystems
12.4 Manipulation of Photosynthesis in Agroforestry
12.4.1 Choice of Species
12.4.2 Shade Management
12.5 Conclusion
References
Chapter 13: Multipurpose Trees (MPTs) and Other Agroforestry Species
13.1 Introduction
13.2 Agroforestry Species
13.3 Multipurpose Trees (MPTs)
13.3.1 Fodder Trees
13.3.2 Fuelwood Trees
13.3.3 Fruit Trees (see also Chapter 23, Section 23.3.1)
13.3.4 Other Underexploited Woody Perennials
13.3.5 MPT Databases
13.3.6 MPT Species Profiles
13.4 Lesser-Known Agroforestry Species
13.4.1 Shade-Tolerant Specialty Crops and Medicinal & Aromatic Plants
13.4.2 Agronomic and Horticultural Species in Agroforestry Systems
13.4.3 Overexploited (Endangered) Species
13.5 Tree Improvement in Agroforestry
13.5.1 A Brief Account of Accomplishments
13.5.2 Ideotypes of Agroforestry Trees?
13.6 Concluding Remarks
Appendices
Appendix I: Short Descriptions of Multipurpose Trees and Shrubs (MPTs) Commonly Used in Agroforestry Systems
Appendix II Shade-Tolerant Specialty Species
Black pepper (Piper nigrum, Family: Piperaceae)
Vanilla (Vanilla planifolia, Family: Orchidaceae)
Cardamom (Elettaria cardamomum, Family: Zingiberaceae)
Large Cardamom (Amomum subulatum, A. aromaticum, Family: Zingiberaceae)
Ginger (Zingiber officinale, Family: Zingiberaceae)
Turmeric (Curcuma longa, Family: Zingiberaceae)
Ginseng: Panax ginseng (Korean ginseng); P. quinquefolium (American ginseng), Family: Aralioideae
Allspice (Pimenta dioica, Family: Myrtaceae)
Cinnamon (Cinnamomum zeylanicum)
Nutmeg (Myristica fragrans, Myristicaceae)
References
Chapter 14: Plant-to-Plant (Tree-Crop) Interactions in Agroforestry Systems
14.1 Introduction
14.2 Tree-Crop Interactions: Shifting Paradigms
14.3 The Complexity of Tree-Crop Interactions
14.3.1 Different Ways of Looking at Interactions
14.3.2 Root Plasticity and Belowground Interactions
14.3.3 Multiple Factors and Processes of Interactions
14.4 Measurement of Tree-Crop Interactions
14.4.1 Crop Yields as Indicators
14.4.2 Land Equivalent Ratio
14.4.3 Tree-Crop Interaction Models
14.5 Management of Tree-Crop Interactions
14.6 Concluding Remarks
References
Section IV: Biophysical Foundations of Agroforestry: Soil Productivity and Protection
Chapter 15: Soils and Agroforestry: General Principles
15.1 Introduction
15.2 Soils and Agroforestry
15.3 Soil Formation
15.3.1 How is the Soil Formed?
15.3.2 Soil Horizon and Soil Profile
15.4 Soil Properties
15.4.1 Physical Properties
How heavy is a soil?
15.4.2 Chemical Properties
15.4.3 Biological Properties
15.5 Soil Types and Soil Classification
15.5.1 The USDA Soil Classification (Soil Taxonomy)
15.5.2 The US Soil Taxonomy and UN (FAO/UNESCO) Soil Classification
15.6 Plant Nutrients in Soils
15.7 Tropical Soils
15.8 Soil Health
References
Chapter 16: Soil Organic Matter (SOM) and Nutrient Cycling
16.1 Introduction
16.2 Soil Organic Matter
16.3 Organic Matter Decomposition
16.3.1 Rates of Organic Matter Decomposition
16.3.2 Litter Quality
16.3.3 Synchronizing Nutrient Release with Plant Uptake
16.4 Nutrient Cycling
16.4.1 The General Concept of Nutrient Cycling
16.4.2 Nutrient Cycling in Agroforestry Systems
16.4.3 Management of Litter Decomposition for Nutrient Use Efficiency
16.5 Soil Fertility Improvement through Trees in Agroforestry Systems
16.5.1 Tree Biomass and Its Decomposition
16.5.2 Tree Roots
16.5.3 Deep Capture of Nutrients
16.6 Concluding Remarks
References
Chapter 17: Biological Nitrogen Fixation and Nitrogen Fixing Trees
17.1 Introduction
17.2 Dinitrogen Fixation
17.3 Rhizobia and the Root-Nodule
17.3.1 Rhizobia
17.3.2 The Root Nodule
17.4 Nitrogen-Fixing Plants
17.4.1 The Family Leguminosae (Fabaceae)
17.4.2 Actinorhizal Plants
17.5 Symbiotic Nitrogen Fixation (SNF) in Woody Perennials
17.5.1 Estimates of SNF by Trees
17.5.2 Factors Affecting SNF by Woody Perennials
17.5.3 Mycorrhizal Infection of Legume Roots to Stimulate Nodulation
17.6 Measurement of Symbiotic Nitrogen Fixation
17.6.1 Acetylene Reduction Assay (ARA)
17.6.2 The Difference Method
17.6.3 The 15N Isotopic Methods
17.6.4 Xylem-Solute Method
17.6.5 Other Methods for Comparing Nitrogen Fixation
17.7 Transfer of Symbiotically Fixed Nitrogen
17.7.1 Nitrogen Transfer Pathways
17.7.2 Factors Affecting Nitrogen Transfer
17.7.3 Methodological Considerations
17.7.4 Nitrogen Gains of Non-NFTs in Mixed-Species Plantations with NFTs
17.8 Managing the Microsymbionts in Agroforestry
17.8.1 Legume Inoculation
17.8.2 Establishment of the Microsymbiont
17.9 Concluding Remarks
References
Chapter 18: Soil Conservation and Control of Land-Degradation
18.1 Introduction
18.2 Soil Conservation
18.3 Historical Developments in Soil Erosion
18.4 Water Erosion
18.4.1 General Principles and Considerations
18.4.2 Measurement of Soil Erosion by Water
18.4.3 Effect of Agroforestry Systems on USLE Soil Erosion Factors
18.4.4 Agronomic Approaches to Water Erosion Control
18.5 Wind Erosion
18.5.1 Wind Erosion: Nature and Measurement
18.5.2 Windbreaks and Shelterbelts (in the Tropics)
18.5.3 Soil Erosion Rates Under Agroforestry Systems
18.6 Land Degradation
18.6.1 Definitions and Characteristics of Land Degradation
18.6.2 The Nature and Extent of Land Degradation
18.7 Agroforestry for the Control of Soil Erosion and Land Degradation: Some Notable Large-Scale Field Projects in the Tropics
18.7.1 Country-Specific Projects (Before 2000)
18.7.2 Multi-country Projects (Current: Post 2015)
18.7.3 ``Biodrainage´´ and Agroforestry for Reclamation of Saline Soils
18.8 Concluding Remarks
References
Section V: Ecosystem Services of Agroforestry
Chapter 19: Ecosystem Services of Agroforestry: An Introduction
19.1 Introduction
19.2 Global Assessments of Ecosystem Services
19.3 Ecosystem Services of Agroforestry
References
Chapter 20: Carbon Sequestration and Climate Change Mitigation
20.1 Introduction
20.2 Climate Change: The Language, Extent, Causes, and Consequences
20.2.1 Definition
20.2.2 Causes of Climate Change: The Greenhouse Gases
20.2.3 The Extent and Impact of Climate Change
20.2.4 Global Initiatives for Combating Climate Change
20.2.5 Climate Change Mitigation and Adaptation
20.3 Carbon Sequestration
20.3.1 Definition and Concepts
20.3.2 Aboveground (Vegetation) Carbon Sequestration
20.3.3 Belowground (Soil) Carbon Sequestration
20.3.4 Mechanisms of Soil Carbon Sequestration
20.3.5 Soil Aggregates and Their Importance in Soil Carbon Sequestration
20.4 Measurement and Estimation of Carbon Sequestration in Agroforestry Systems
20.4.1 Vegetation
20.4.2 Belowground (Soils)
20.4.3 Methodological Difficulties
20.5 Reported Data on Carbon Sequestration Under Agroforestry Systems
20.5.1 Soil Carbon Sequestration: Results from a Set of Multi-locational Studies
20.5.2 Meta-analyses
20.5.3 Carbon Saturation in Soils
20.5.4 Carbon Sequestration Potential of Agroforestry Systems: Summary
20.6 Agroforestry Management for Carbon Storage and Climate-Change Mitigation
20.6.1 Biochar Use in Agroforestry
20.6.2 Tree Selection and Management
20.6.3 Mitigation and Adaptation Strategies
20.6.4 Development Agendas and Paradigms
20.7 Concluding Remarks
References
Chapter 21: Agroforestry for Biodiversity Conservation
21.1 Introduction
21.2 Biodiversity Conservation: A Major Global Environmental Issue
21.3 What is Biodiversity?
21.3.1 Biodiversity: Definitions Galore
21.3.2 Measuring Biodiversity
21.4 Agrobiodiversity or Farmland Biodiversity
21.5 Other Subsets of Biodiversity
21.6 Agroforestry for Biodiversity Conservation
21.6.1 Biodiversity Hotspots and ``Coldspots´´
21.6.2 Agroforestry for Offsetting Threats to Agrobiodiversity
21.6.3 Species Diversity in Agroforestry
21.6.4 Habitat Diversity: Some Empirical Aspects
21.6.5 Pathways for Conservation of Tree Diversity in Smallholder Agroforestry Systems
21.6.6 Land Sharing Strategy for Biodiversity Conservation in Agricultural Landscapes
21.7 Ecosystem Resilience
21.8 Concluding Remarks
References
Chapter 22: Other Ecosystem Services of Agroforestry
22.1 Introduction
22.2 Hydrological Characteristics and Soil Water Storage
22.3 Water Quality Enhancement
22.4 Cultural Ecosystem Services (CES)
22.4.1 Traditional Ecological Knowledge
22.4.2 Ethnoforestry and Tropical Homegardens as Providers of CES
22.5 Plant Health: Control of Pests, Diseases, and Weeds
22.6 Opportunities for Agroforestry Hot Spots as Biodiversity and Ecotourism Attractions
References
Section VI: Sustainable Development, Agroforestry, and Land Management in the Future
Chapter 23: Food Security, Agroforestry, and Sustainable Development Goals
23.1 Introduction
23.2 Agroforestry and Food Security
23.3 Direct Role of Agroforestry in Food Security
23.3.1 Fruit Trees
23.3.2 Nutritional Security
23.4 Indirect Role of Agroforestry in Food Security
23.5 The Way Forward
Annexure I
U. N. Sustainable Development Goals (2015) (https://www.un.org/sustainabledevelopment/sustainable-development-goals)
References
Chapter 24: Agroforestry and Land Management in the Future
24.1 Introduction
24.2 The Past
24.3 The Present
24.4 The Future
References
Acronyms and Abbreviations
Glossary
Appendix
SI Units and Conversion Factors
1 SI Units
1.1 The SI Base Units
1.2 SI Derived Units
1.3 SI Prefixes
1.4 Non-SI Units
1.5 SI Conventions
1.5.1 Unit Symbols
1.5.2 Unit Names
1.5.3 Formatting the Value of a Quantity
1.5.4 Formatting Numbers, and the Decimal Marker
1.5.5 Multiplying or Dividing Quantity Symbols, the Values of Quantities, or Numbers
1.5.6 Stating Quantity Values Being Pure Numbers
2 Conversion Factors
2.1 Basic Conversion Factors
2.2 Conversion Factors for SI and Non-SI Units (Source: ASA, CSSA, and SSSA, 2020)
References
Subject Index