This book contains a collection of 14 case studies from around the globe that illustrate the impact of a range of land-use changes on the physical, chemical and biological characteristics of soils and provide a snapshot of the challenges faced in ensuring sustainable soil management in tropical and savannah environments. This book is not a comprehensive account of all the drivers of soil change in the tropics, nor does it cover all areas of the tropics. It does, however, take a broad view of the tropics, with the inclusion of studies from South Africa and the dry sub-humid tropics of the Kalahari as well as the humid tropics. Tropics are drawn from a wide geographical area including South and Central America, South East Asia, India and Africa, and the chapters have been contributed by authors from all of these areas as well as Europe, North America, Australasia and Japan. It thus provides a snapshot of a range of factors affecting soils across the globe. From this, emerges topics that can be grouped into the following themes: the effects of land-use change on soil microbial populations; urban soils, agriculture and soil contamination; and land-use effects on soil carbon and soil organic matter.

• Land-use Change Impacts on Soil Processes: Tropical and Savannah Ecosystems
• Copyright
• Contents
• Contributors
• Acknowledgements
• 1: Land-use Change Impacts on Soil Processes in Tropical and Savannah Ecosystems: An Introduction
  • 1.1 Introduction
  • 1.2 The Importance of Soil to Human Well-being
  • 1.3 Land-use Change and Soil Properties
  • 1.4 Themes and Scope of this Book
    • 1.4.1 The effects of land-use change on soil microbial populations
    • 1.4.2 Urban soils, agriculture and soil contamination
    • 1.4.3 Land-use effects on soil carbon and soil organic matter
  • References
• 2: Effects of Land-use Changes on Biochemical and Microbial Parameters in Soils of the Andaman Islands, India
  • 2.1 Introduction
  • 2.2 Materials and Methods
    • 2.2.1 Study site
    • 2.2.2 Soil sampling
    • 2.2.3 Soil biochemical/microbial parameters
    • 2.2.4 Statistical analyses
  • 2.3 Results
    • 2.3.1 Soil microbial biomass
    • 2.3.2 Soil respiration
    • 2.3.3 Adenylates and adenylate energy charge
    • 2.3.4 Ergosterol
  • 2.4 Discussion
  • 2.5 Conclusions
  • References
• 3: Evaluating the Impact of Oil Palm Agriculture and Logging on Soil Microbial Communities in South-east Asia
  • 3.1 Introduction
  • 3.2 Methods
    • 3.2.1 Study site
    • 3.2.2 Sampling scheme
    • 3.2.3 Soil and microbial analyses
    • 3.2.4 Statistical analyses
  • 3.3 Results
  • 3.4 Discussion
  • 3.5 Conclusions
  • Acknowledgements
  • References
• 4: Microbial Functioning in Response to a Simulated Drought in Malaysian Rain Forest and Oil Palm Soils
  • 4.1 Introduction
  • 4.2 Methods
  • 4.3 Results
  • 4.4 Discussion
  • 4.5 Conclusions
  • Acknowledgements
  • References
• 5: Impact of Land-use Changes in the Amazon on Bacterial Diversity, Composition and Distribution
  • 5.1 Introduction
  • 5.2 Assessment of Soil Quality Based on Microbial Community Structure and Function in the Tropics
  • 5.3 Studies on Microbial Community Structure and Function in Amazonian Soils
  • 5.4 Conclusions
  • Acknowledgements
  • References
• 6: Acidification of Tropical Soils under Forest and Continuous Cropping in Thailand and Indonesia
  • 6.1 Introduction
  • 6.2 Materials and Methods
    • 6.2.1 Study sites
    • 6.2.2 Sampling and analytical methods for soil and plant materials
    • 6.2.3 Measurements of decomposition rates and stocks of organic matter
    • 6.2.4 Sampling and analytical methods of precipitation, throughfall and soil solution
    • 6.2.5 Calculation of proton budgets
    • 6.2.6 Calculations and statistical analyses
  • 6.3 Results
    • 6.3.1 Physicochemical properties of soils
    • 6.3.2 Decomposition rates of soil organic matter
    • 6.3.3 Composition of soil solution
    • 6.3.4 Net proton generation and consumption
  • 6.4 Discussion
    • 6.4.1 Natural acidification processes of tropical forest soils
    • 6.4.2 Soil acidification processes in cropland soils
    • 6.4.3 Effects of continuous cropping on organic matter cycles and soil acidification
    • 6.4.4 Soil acidification and implications for amelioration strategy in Asian countries
  • 6.5 Conclusions
  • References
• 7: The Importance of Soil Quality in the Safe Practice of Urban Agriculture in Zimbabwe, Kenya and South Africa
  • 7.1 Introduction: Urban Soils as Vital Pseudo-natural Capital
    • 7.1.1 Urban soils as distinct entities
    • 7.1.2 Risks associated with cultivation of urban soils
    • 7.1.3 Emerging pressures on urban natural capital
  • 7.2 The Development of Urban Agriculture in Africa
    • 7.2.1 Origins and progress
    • 7.2.2 The economic value of urban agriculture in Africa
    • 7.2.3 Planning, policy and opposition to urban agriculture
    • 7.2.4 Urban agriculture and its impact on African soils
  • 7.3 Urban Agriculture in Africa: A Selection of Case Studies
    • 7.3.1 The practice of urban agriculture in Harare – Zimbabwe
    • 7.3.2 The practice of urban agriculture in Nairobi – Kenya
    • 7.3.3 The practice of urban agriculture in Johannesburg – South Africa
  • 7.4 Conclusions: The Future of Urban Agriculture and Soils in Africa
  • References
• 8: Urbanization and Soil Nutrient Challenges and Opportunities: Lessons from Malawian Cities
  • 8.1 Introduction
  • 8.2 Methods
    • 8.2.1 Study sites
    • 8.2.2 Urban agriculture and livelihoods
    • 8.2.3 Soil nutrient budgets
    • 8.2.4 Assessing the effect of ecosanitation manure on maize yield and community perceptions
  • 8.3 Results
    • 8.3.1 Urban agriculture and livelihoods
    • 8.3.2 Soil nutrient budgets
    • 8.3.3 Ecological sanitation plots
  • 8.4 Discussion
  • 8.5 Conclusions
  • Acknowledgements
  • References
• 9: Impact of Gold Mining on Mercury Contamination and Soil Degradation in Amazonian Ecosystems of French Guiana
  • 9.1 Introduction
  • 9.2 Origins and carrier phases of mercury accumulated in soils
  • 9.3 Soil Processes Controlling Mercury Concentrations in Soils
  • 9.4 Relative Importance of Mercury Anthropogenic Inputs versus Geochemical Background
  • 9.5 Mobilization of Mercury from Soils
  • 9.6 Methylation of Mercury in Former Gold-mined Sites
  • 9.7 Recent Legislative Attempts to Reduce Mercury Emissions and Methylation
  • 9.8 Conclusions
  • References
• 10: Erosion and Sedimentation Effects on Soil Organic Carbon Redistribution in a Complex Landscape in Western Ecuador
  • 10.1 Introduction
  • 10.2 Materials and Methods
    • 10.2.1 Study site
    • 10.2.2 Site selection, soil sampling and measurement of soil organic carbon
    • 10.2.3 Modelling and statistical analyses
  • 10.3 Results
    • 10.3.1 Soil organic carbon baseline
    • 10.3.2 Impacts of erosion and sedimentation by land-use change on SOC redistribution
  • 10.4 Discussion
    • 10.4.1 Soil organic carbon baseline
    • 10.4.2 Soil redistribution and SOC balance under different land-use change scenarios
    • 10.4.3 Land-use policy options
  • Acknowledgements
  • References
• 11: Pastoralism and Kalahari Rangeland Soils
  • 11.1 Introduction
  • 11.2 Methods
    • 11.2.1 Study site
    • 11.2.2 Field experiment 1: Grazing disturbance simulation
    • 11.2.3 Field experiment 2: Soil properties and microclimate under vegetation and in open-grass sites
    • 11.2.4 Statistical analyses
  • 11.3 Results
    • 11.3.1 The impact of intense and light grazing on SOC, chlorophyll a and CO2 efflux
    • 11.3.2 Differences in microclimate, SOC and soil CO2 efflux in open-grass and vegetation canopy sites
  • 11.4 Discussion
    • 11.4.1 Grazing and soils in rangelands
    • 11.4.2 The spatial distribution of resources and links to degradation
  • 11.5 Conclusions
  • Acknowledgements
  • References
• 12: Changes in Soil Properties with Sugarcane Cropping in Mauritius
  • 12.1 Introduction and Review of Literature
  • 12.2 Materials and Methods
  • 12.3 Results
    • 12.3.1 Soil biological properties
    • 12.3.2 Loss of native SOC and its replacement by sugarcane-derived C
    • 12.3.3 Soil chemical properties
    • 12.3.4 Soil physical properties
  • 12.4 Discussion
  • 12.5 Conclusions
  • References
• 13: Patterns and Drivers of Soil Carbon Stocks and Isotopic Composition in Secondary Tropical Dry Forests of Costa Rica
  • 13.1 Introduction
  • 13.2 Methods
    • 13.2.1 Study site
    • 13.2.2 Plot locations and assumptions about prior land-use history
    • 13.2.3 Soil and vegetation sampling in forests
    • 13.2.4 Grasslands
    • 13.2.5 Plant material for isotope analysis
    • 13.2.6 Laboratory analyses
    • 13.2.7 Soil carbon inventories
    • 13.2.8 Calculations of pastureversus forest-derived C
    • 13.2.9 Statistical analyses
  • 13.3 Results
    • 13.3.1 Patterns with forest age
    • 13.3.2 Correlates of soil C and
  • 13.4 Discussion
    • 13.4.1 Successional patterns
    • 13.4.2 Soil-forming factors and soil C storage
    • 13.4.3 Insights from stable isotopes
    • 13.4.4 Methodological considerations
  • 13.5 Conclusions
  • Acknowledgements
  • References
• 14: Conversion of Pastures into Tectona grandis Plantations in Western Panamá: Effects on Soil Properties and the Mechanisms Underlying these Changes
  • 14.1 Introduction
  • 14.2 Materials and Methods
    • 14.2.1 Study site
    • 14.2.2 Land-use type, site and plot selection
    • 14.2.3 Soil and root sampling
    • 14.2.4 Laboratory analyses
    • 14.2.5 Calculation of carbon and nitrogen stocks in mineral soil and roots
    • 14.2.6 Statistical analyses
  • 14.3 Results
    • 14.3.1 Physical and chemical soil properties
    • 14.3.2 Soil carbon and nitrogen
    • 14.3.3 Fine root biomass and carbon stocks
  • 14.4 Discussion
    • 14.4.1 Land-use history, soil mineralogy, site preparation and management
    • 14.4.2 Species effects and soil–plant interactions
    • 14.4.3 Plantation age
    • 14.4.4 Consequences of teak establishment on soil quality, soil C storage and plant diversity
  • 14.5 Conclusions
  • Acknowledgements
  • References
• 15: Land-use Change Impacts on Soil Processes in Tropical and Savannah Ecosystems: Emerging Themes and Future Research Directions
  • 15.1 Emerging Themes in Land-use Change Effects on Soils in the Tropics
  • 15.2 Working at Appropriate Scales to Address Relevant Questions About Land Management
  • 15.3 Adopting a Holistic Approach to Understanding Soil Functioning and Fertility
  • 15.4 Utilizing New Molecular Techniques to Test Hypotheses Relating to Soil Processes and the Impacts of Land Use
  • 15.5 Reconciling the Multiple Demands on Soils in Rural and Urban Settings
  • 15.6 A Way Forward
  • References
• Index