Jacques Berthelin is former Research Director at CNRS and a member of the Académie d'Agriculture de France, Paris.Christian Valentin, a member of the Académie d'Agriculture de France, is Research Director at IRD and Deputy Director of the Institut d'Ecologie et des Sciences de l'Environnement, Paris.Jean Charles Munch is Emeritus Professor at the Technical University of Munich in Germany and former Director of the Institute of Soil Ecology at Helmholtz Zentrum München. He is also a member of the Académie d'Agriculture de France.

• Foreword xiiiChapter 1. Soils as a Key Component of the Critical Zone 1Jacques BERTHELIN, Guilhem BOURRIÉ, Michel-Claude GIRARD, Guillaume DHÉRISSARD and Christian VALENTIN1.1. What are soils? 11.2. The Earth, land, soils, soil cover and the Critical Zone 21.3. The term “soil” has various meanings according to use   and function processes 51.4. The concept of soil varies according to the user 61.4.1. Agricultural sector 71.4.2. Scientific communities 71.4.3. Urban communities 81.4.4. Current pressures and questions 81.5. The approaches and procedures of soil scientists and pedologists 91.6. Two principles to take into account: geographical continuity and multi-temporality 101.6.1. Principle of continuity 101.6.2. Principle of multi-temporality 131.7. Nature, organization and major modes of soil processes 151.7.1. Soils before the arrival of humans 151.7.2. Specifics and origins of the Earth’s soils 171.7.3. The parameters controlling differentiation and diversity of soils 181.8. The functions and services of soils 231.8.1. Major functions 231.8.2. Services provided by soils 241.8.3. The role of soils within our culture and our history 251.9. The need and significance of soil information systems 291.10. Conclusion and recommendation 291.11. Bibliography 30Chapter 2. Understanding Soils for Their More Efficient Management: A National Soil Information System 35Marion BARDY, Dominique ARROUAYS, Claudy JOLIVET, Bertrand LAROCHE, Christine LE BAS, Manuel MARTIN, Céline RATIÉ, Anne C. RICHER-DE-FORGES, Nicolas SABY, Véronique ANTONI, Antonio BISPO, Michel BROSSARD, Jean-Luc FORT, Joëlle SAUTER and Chantal GASCUEL2.1. Introduction 352.2. The inventory and monitoring of soils in Europe and in the world 362.3. National mechanisms for the acquisition of soil data 372.3.1. Issues and demands 372.3.2. Structuring of national data collection mechanisms 382.4. Data exploitation for the production of maps and indicators 442.5. Dissemination and availability of data 492.5.1. A national soil information system focused on data dissemination 492.5.2. A progressive enrichment of data and metadata supply 502.5.3. Assisting the use, improvement and control of data 522.6. Conclusion 522.7. Bibliography 53Chapter 3. Soils and Regulation of the Hydrological Cycle 9Marc VOLTZ, Cécile DAGÈS, Laurent PRÉVOT and Ary BRUAND3.1. The soil – facilitator within the hydrological cycle 593.2. Soil control mechanisms 613.2.1. Infiltration–runoff partition 613.2.2. Aquifer recharge 653.2.3. Evaporation and transpiration flows 673.2.4. Capillary rise 703.2.5. Soil water budget 713.2.6. Hydrological flows along hillslopes 723.3. Impacts on the hydrological cycle at soil cover scale 743.3.1. Influence of soil and land use variations 753.3.2. Influence of land use changes 773.3.3. Influence of landscape infrastructures 783.4. Conclusions 79Chapter 4. Soils as Bio-physicochemical Reactors 81Fabienne TROLARD and Guilhem BOURRIÉ4.1. What is a reactor? 814.2. Soil components 854.3. Reactivity drivers 864.4. Main reactions within soils 904.4.1. Master variables: pH and pe 904.4.2. Acid–base reactions 914.4.3. Reactions of oxido-reduction 944.4.4. Degradation of organic matter 954.5. Biogeochemical evolution of the Earth’s surface and the consequences for soils 964.5.1. Availability of chemical elements changed with the Earth’s evolution 964.5.2. The evolution of the Earth’s reactor imposed the evolution of living organisms 994.5.3. Emergence of the “soil” function within the Critical Zone 1014.6. Soil, biogeochemical reactor of soil formation 1034.6.1. Vertical dynamics of soils: the lowering of horizons within landscapes 1054.6.2. Lateral dynamics of soil and transformations of soil covers 1074.6.3. Lateral dynamics by epigenesis (replacement) 1114.7. Soil structure: a case of “soft matter” 1124.8. Bibliography 113Chapter 5. Soils are Biosystems, Habitats and Reserves of Biodiversity 117Jacques BERTHELIN, Éric BLANCHART, Jean TRAP and Jean Charles MUNCH5.1. Introduction 1175.2. Emergence and development of microbial ecology and soil biology 1185.2.1. Discovery of the microbial world, a turning point in the knowledge of the functioning of soil–plant systems 1185.2.2. Discovery of the role of fauna and development of soil biology 1195.3. Soil microbial communities 1195.3.1. Richness and diversity of microbial communities 1195.3.2. Evolution of methodologies in soil microbial ecology 1235.4. Diversity of energy and nutritional pathways of microorganisms, key players in biogeochemical cycles 1245.4.1. Heterotrophy, autotrophy and extreme environments 1245.4.2. Soils, environments where life is active with or without oxygen 1255.5. Richness and diversity of soil fauna 1265.5.1. Diversity of soil fauna 1265.5.2. Classification by size 1275.5.3. Functional classification sensu lato 1275.5.4. Characterization of the fauna 1285.6. Soils, environments with energy and nutritional conditions favorable to microbial life and fauna 1285.7. Determinants and remarkable sites of diversity and soil biological activities 1295.7.1. Parameters and major activity sites 1295.7.2. Impact of land use 1305.7.3. Humus, integrators and developers of specific biological activities 1315.7.4. The rhizosphere, a site of major interactions of soil–plant systems 1325.8. Tools for understanding the habitats of soil organisms 1335.9. Specificities of the soil fauna 1335.9.1. Microregulators 1345.9.2. The communities of organisms called “engineers” 1345.10. Soil organisms: ecosystem service actors 1355.11. Soil quality indicators 1375.11.1. Soil organisms as indicators 1375.11.2. Ecological functions as indicators 1385.12. Conclusion and perspectives 1385.13. Bibliography 139Chapter 6. Soils, a Factor in Plant Production:Agroecosystems 147Claire CHENU, Jean ROGER-ESTRADE, Chantal GASCUEL and Christian WALTER6.1. Introduction 1476.2. Evolution of soil–agriculture relationship over the last few decades 1486.3. Agricultural capability of soils 1506.3.1. How do we define the agricultural capability of a soil? 1506.3.2. Limited soil resources on a global scale 1546.4. Agricultural practices that alter soil properties 1556.5. Toward sustainable management of agricultural soils 1586.6. Conclusion 161Chapter 7. Forest Soils: Characteristics and Sustainability 163Jacques RANGER7.1. Forest soils 1637.2. Bioavailability of nutrients: soil–plant coevolution and the role of the biological cycle 1657.3. Concept of forest soil fertility 1707.4. Specificity of forest soils compared to agricultural soils 1717.5. Threats to forest soils 1757.5.1. Acidification 1757.5.2. Physical degradation 1777.5.3. The particular problem of organic carbon: soil fertility and climate change 1797.5.4. Maintaining biodiversity 1807.5.5. Pollution 1817.5.6. Disappearance of forest soils 1817.6. Conclusions 1817.7. Bibliography 183Chapter 8. Soils and Energy 187Isabelle FEIX8.1. Soils at the heart of global issues 1878.2. Energy context 1888.3. Soils, energy supports and energy suppliers 1908.3.1. Forest and agricultural biomass production: for bioenergy production 1908.3.2. Physical supports of renewable energy: ground-mounted photovoltaic power plants and onshore wind turbines 1908.3.3. Heat and freshness supplies: horizontal superficial geothermal energy and climatic wells 1918.3.4. Peat: formerly used as a biofuel 1918.4. The consequences of energy production on mobilization, occupation and land-use change 1928.4.1. Comparison of land use intensities and land area occupations for energy production 1948.4.2. Comparison of land use changes related to different energies 2028.4.3. Consequences of energy policies for land mobilization and LUC 2048.4.4. Optimization of land use 2068.5. Impacts of energy production on soil loss, degradation and quality 2078.5.1. Impacts common to all energies 2078.5.2. Peat 2088.5.3. Fossil fuels 2088.5.4. Nuclear energy 2088.5.5. Solar and wind energies 2098.5.6. Bioenergies 2108.6. Conclusion 2178.7. Bibliography 219Chapter 9. Soils, Materials, and Infrastructure Supports 233Guilhem BOURRIÉ and Fabienne TROLARD9.1. The use of “raw” soils as building materials 2339.2. Soils, infrastructure supports 2369.3. The classical civil engineering versus the physical approach of granular media 2379.4. Consumption of agricultural land, forest or natural areas by urban sprawl 2399.5. The use of separate particle size fractions 2429.5.1. The use of coarse fractions 2429.5.2. The use of the clay fraction as material and reaction support 2429.5.3. The use of the soil organic fraction 2439.5.4. The use of soil oxides 2439.6. The use of chemical elements after extraction and treatment 2439.7. Bibliography 244Chapter 10. Cultural Dimensions of Soils 247Suzanne MÉRIAUX and Michel-Claude GIRARD10.1. Soil representations – the Earth celebrated 24710.1.1. The written Earth 24810.1.2. The illustrated Earth 25110.1.3. The Earth with sound 25410.2. Humanity, Earth and soil: myths and rites 25810.2.1. Defining myths 25910.2.2. Earth and soils in myths 25910.2.3. Myths 26110.2.4. Rites 26810.2.5. Analogies with the pedological approach? 26910.2.6. Links between humans and earth/soils 27010.2.7. Conclusion 27110.3. Bibliography 272Chapter 11. Environmental and Societal Memories of Soils 275Marie-Agnès COURTY11.1. Ancient soils: archives of human history 27511.1.1. Objectives 27511.1.2. Soil memory and climate change 27611.1.3. Memory of ancient soils and societies 27811.2. Methods of studying soil memory 27911.2.1. The field approach 27911.2.2. Analytical characterization 28111.3. Reading the ancient soil memory 28211.3.1. Foundations 28211.3.2. Sedimentary features 28311.3.3. Combustion features 28511.3.4. Soil features 28711.4. Conclusion and perspectives 29411.5. Bibliography 295Chapter 12. A Mesological Point of View 299Pierre DONADIEU12.1. Soil ubiquity 29912.2. Soil as 30112.3. Off-ground? 30312.4. Living off-ground 30412.5. Limits of the off-ground 30712.6. Conclusion 30912.7. Bibliography 309List of Authors 311Index 315

Jacques Berthelin is former Research Director at CNRS and a member of the Académie d'Agriculture de France, Paris.Christian Valentin, a member of the Académie d'Agriculture de France, is Research Director at IRD and Deputy Director of the Institut d'Ecologie et des Sciences de l'Environnement, Paris.Jean Charles Munch is Emeritus Professor at the Technical University of Munich in Germany and former Director of the Institute of Soil Ecology at Helmholtz Zentrum München. He is also a member of the Académie d'Agriculture de France.

• Foreword xiiiChapter 1. Soils as a Key Component of the Critical Zone 1Jacques BERTHELIN, Guilhem BOURRIÉ, Michel-Claude GIRARD, Guillaume DHÉRISSARD and Christian VALENTIN1.1. What are soils? 11.2. The Earth, land, soils, soil cover and the Critical Zone 21.3. The term “soil” has various meanings according to use   and function processes 51.4. The concept of soil varies according to the user 61.4.1. Agricultural sector 71.4.2. Scientific communities 71.4.3. Urban communities 81.4.4. Current pressures and questions 81.5. The approaches and procedures of soil scientists and pedologists 91.6. Two principles to take into account: geographical continuity and multi-temporality 101.6.1. Principle of continuity 101.6.2. Principle of multi-temporality 131.7. Nature, organization and major modes of soil processes 151.7.1. Soils before the arrival of humans 151.7.2. Specifics and origins of the Earth’s soils 171.7.3. The parameters controlling differentiation and diversity of soils 181.8. The functions and services of soils 231.8.1. Major functions 231.8.2. Services provided by soils 241.8.3. The role of soils within our culture and our history 251.9. The need and significance of soil information systems 291.10. Conclusion and recommendation 291.11. Bibliography 30Chapter 2. Understanding Soils for Their More Efficient Management: A National Soil Information System 35Marion BARDY, Dominique ARROUAYS, Claudy JOLIVET, Bertrand LAROCHE, Christine LE BAS, Manuel MARTIN, Céline RATIÉ, Anne C. RICHER-DE-FORGES, Nicolas SABY, Véronique ANTONI, Antonio BISPO, Michel BROSSARD, Jean-Luc FORT, Joëlle SAUTER and Chantal GASCUEL2.1. Introduction 352.2. The inventory and monitoring of soils in Europe and in the world 362.3. National mechanisms for the acquisition of soil data 372.3.1. Issues and demands 372.3.2. Structuring of national data collection mechanisms 382.4. Data exploitation for the production of maps and indicators 442.5. Dissemination and availability of data 492.5.1. A national soil information system focused on data dissemination 492.5.2. A progressive enrichment of data and metadata supply 502.5.3. Assisting the use, improvement and control of data 522.6. Conclusion 522.7. Bibliography 53Chapter 3. Soils and Regulation of the Hydrological Cycle 9Marc VOLTZ, Cécile DAGÈS, Laurent PRÉVOT and Ary BRUAND3.1. The soil – facilitator within the hydrological cycle 593.2. Soil control mechanisms 613.2.1. Infiltration–runoff partition 613.2.2. Aquifer recharge 653.2.3. Evaporation and transpiration flows 673.2.4. Capillary rise 703.2.5. Soil water budget 713.2.6. Hydrological flows along hillslopes 723.3. Impacts on the hydrological cycle at soil cover scale 743.3.1. Influence of soil and land use variations 753.3.2. Influence of land use changes 773.3.3. Influence of landscape infrastructures 783.4. Conclusions 79Chapter 4. Soils as Bio-physicochemical Reactors 81Fabienne TROLARD and Guilhem BOURRIÉ4.1. What is a reactor? 814.2. Soil components 854.3. Reactivity drivers 864.4. Main reactions within soils 904.4.1. Master variables: pH and pe 904.4.2. Acid–base reactions 914.4.3. Reactions of oxido-reduction 944.4.4. Degradation of organic matter 954.5. Biogeochemical evolution of the Earth’s surface and the consequences for soils 964.5.1. Availability of chemical elements changed with the Earth’s evolution 964.5.2. The evolution of the Earth’s reactor imposed the evolution of living organisms 994.5.3. Emergence of the “soil” function within the Critical Zone 1014.6. Soil, biogeochemical reactor of soil formation 1034.6.1. Vertical dynamics of soils: the lowering of horizons within landscapes 1054.6.2. Lateral dynamics of soil and transformations of soil covers 1074.6.3. Lateral dynamics by epigenesis (replacement) 1114.7. Soil structure: a case of “soft matter” 1124.8. Bibliography 113Chapter 5. Soils are Biosystems, Habitats and Reserves of Biodiversity 117Jacques BERTHELIN, Éric BLANCHART, Jean TRAP and Jean Charles MUNCH5.1. Introduction 1175.2. Emergence and development of microbial ecology and soil biology 1185.2.1. Discovery of the microbial world, a turning point in the knowledge of the functioning of soil–plant systems 1185.2.2. Discovery of the role of fauna and development of soil biology 1195.3. Soil microbial communities 1195.3.1. Richness and diversity of microbial communities 1195.3.2. Evolution of methodologies in soil microbial ecology 1235.4. Diversity of energy and nutritional pathways of microorganisms, key players in biogeochemical cycles 1245.4.1. Heterotrophy, autotrophy and extreme environments 1245.4.2. Soils, environments where life is active with or without oxygen 1255.5. Richness and diversity of soil fauna 1265.5.1. Diversity of soil fauna 1265.5.2. Classification by size 1275.5.3. Functional classification sensu lato 1275.5.4. Characterization of the fauna 1285.6. Soils, environments with energy and nutritional conditions favorable to microbial life and fauna 1285.7. Determinants and remarkable sites of diversity and soil biological activities 1295.7.1. Parameters and major activity sites 1295.7.2. Impact of land use 1305.7.3. Humus, integrators and developers of specific biological activities 1315.7.4. The rhizosphere, a site of major interactions of soil–plant systems 1325.8. Tools for understanding the habitats of soil organisms 1335.9. Specificities of the soil fauna 1335.9.1. Microregulators 1345.9.2. The communities of organisms called “engineers” 1345.10. Soil organisms: ecosystem service actors 1355.11. Soil quality indicators 1375.11.1. Soil organisms as indicators 1375.11.2. Ecological functions as indicators 1385.12. Conclusion and perspectives 1385.13. Bibliography 139Chapter 6. Soils, a Factor in Plant Production:Agroecosystems 147Claire CHENU, Jean ROGER-ESTRADE, Chantal GASCUEL and Christian WALTER6.1. Introduction 1476.2. Evolution of soil–agriculture relationship over the last few decades 1486.3. Agricultural capability of soils 1506.3.1. How do we define the agricultural capability of a soil? 1506.3.2. Limited soil resources on a global scale 1546.4. Agricultural practices that alter soil properties 1556.5. Toward sustainable management of agricultural soils 1586.6. Conclusion 161Chapter 7. Forest Soils: Characteristics and Sustainability 163Jacques RANGER7.1. Forest soils 1637.2. Bioavailability of nutrients: soil–plant coevolution and the role of the biological cycle 1657.3. Concept of forest soil fertility 1707.4. Specificity of forest soils compared to agricultural soils 1717.5. Threats to forest soils 1757.5.1. Acidification 1757.5.2. Physical degradation 1777.5.3. The particular problem of organic carbon: soil fertility and climate change 1797.5.4. Maintaining biodiversity 1807.5.5. Pollution 1817.5.6. Disappearance of forest soils 1817.6. Conclusions 1817.7. Bibliography 183Chapter 8. Soils and Energy 187Isabelle FEIX8.1. Soils at the heart of global issues 1878.2. Energy context 1888.3. Soils, energy supports and energy suppliers 1908.3.1. Forest and agricultural biomass production: for bioenergy production 1908.3.2. Physical supports of renewable energy: ground-mounted photovoltaic power plants and onshore wind turbines 1908.3.3. Heat and freshness supplies: horizontal superficial geothermal energy and climatic wells 1918.3.4. Peat: formerly used as a biofuel 1918.4. The consequences of energy production on mobilization, occupation and land-use change 1928.4.1. Comparison of land use intensities and land area occupations for energy production 1948.4.2. Comparison of land use changes related to different energies 2028.4.3. Consequences of energy policies for land mobilization and LUC 2048.4.4. Optimization of land use 2068.5. Impacts of energy production on soil loss, degradation and quality 2078.5.1. Impacts common to all energies 2078.5.2. Peat 2088.5.3. Fossil fuels 2088.5.4. Nuclear energy 2088.5.5. Solar and wind energies 2098.5.6. Bioenergies 2108.6. Conclusion 2178.7. Bibliography 219Chapter 9. Soils, Materials, and Infrastructure Supports 233Guilhem BOURRIÉ and Fabienne TROLARD9.1. The use of “raw” soils as building materials 2339.2. Soils, infrastructure supports 2369.3. The classical civil engineering versus the physical approach of granular media 2379.4. Consumption of agricultural land, forest or natural areas by urban sprawl 2399.5. The use of separate particle size fractions 2429.5.1. The use of coarse fractions 2429.5.2. The use of the clay fraction as material and reaction support 2429.5.3. The use of the soil organic fraction 2439.5.4. The use of soil oxides 2439.6. The use of chemical elements after extraction and treatment 2439.7. Bibliography 244Chapter 10. Cultural Dimensions of Soils 247Suzanne MÉRIAUX and Michel-Claude GIRARD10.1. Soil representations – the Earth celebrated 24710.1.1. The written Earth 24810.1.2. The illustrated Earth 25110.1.3. The Earth with sound 25410.2. Humanity, Earth and soil: myths and rites 25810.2.1. Defining myths 25910.2.2. Earth and soils in myths 25910.2.3. Myths 26110.2.4. Rites 26810.2.5. Analogies with the pedological approach? 26910.2.6. Links between humans and earth/soils 27010.2.7. Conclusion 27110.3. Bibliography 272Chapter 11. Environmental and Societal Memories of Soils 275Marie-Agnès COURTY11.1. Ancient soils: archives of human history 27511.1.1. Objectives 27511.1.2. Soil memory and climate change 27611.1.3. Memory of ancient soils and societies 27811.2. Methods of studying soil memory 27911.2.1. The field approach 27911.2.2. Analytical characterization 28111.3. Reading the ancient soil memory 28211.3.1. Foundations 28211.3.2. Sedimentary features 28311.3.3. Combustion features 28511.3.4. Soil features 28711.4. Conclusion and perspectives 29411.5. Bibliography 295Chapter 12. A Mesological Point of View 299Pierre DONADIEU12.1. Soil ubiquity 29912.2. Soil as 30112.3. Off-ground? 30312.4. Living off-ground 30412.5. Limits of the off-ground 30712.6. Conclusion 30912.7. Bibliography 309List of Authors 311Index 315

Jacques Berthelin is former Research Director at CNRS and a member of the Académie d'Agriculture de France, Paris.Christian Valentin, a member of the Académie d'Agriculture de France, is Research Director at IRD and Deputy Director of the Institut d'Ecologie et des Sciences de l'Environnement, Paris.Jean Charles Munch is Emeritus Professor at the Technical University of Munich in Germany and former Director of the Institute of Soil Ecology at Helmholtz Zentrum München. He is also a member of the Académie d'Agriculture de France.

• Foreword xiiiChapter 1. Soils as a Key Component of the Critical Zone 1Jacques BERTHELIN, Guilhem BOURRIÉ, Michel-Claude GIRARD, Guillaume DHÉRISSARD and Christian VALENTIN1.1. What are soils? 11.2. The Earth, land, soils, soil cover and the Critical Zone 21.3. The term “soil” has various meanings according to use   and function processes 51.4. The concept of soil varies according to the user 61.4.1. Agricultural sector 71.4.2. Scientific communities 71.4.3. Urban communities 81.4.4. Current pressures and questions 81.5. The approaches and procedures of soil scientists and pedologists 91.6. Two principles to take into account: geographical continuity and multi-temporality 101.6.1. Principle of continuity 101.6.2. Principle of multi-temporality 131.7. Nature, organization and major modes of soil processes 151.7.1. Soils before the arrival of humans 151.7.2. Specifics and origins of the Earth’s soils 171.7.3. The parameters controlling differentiation and diversity of soils 181.8. The functions and services of soils 231.8.1. Major functions 231.8.2. Services provided by soils 241.8.3. The role of soils within our culture and our history 251.9. The need and significance of soil information systems 291.10. Conclusion and recommendation 291.11. Bibliography 30Chapter 2. Understanding Soils for Their More Efficient Management: A National Soil Information System 35Marion BARDY, Dominique ARROUAYS, Claudy JOLIVET, Bertrand LAROCHE, Christine LE BAS, Manuel MARTIN, Céline RATIÉ, Anne C. RICHER-DE-FORGES, Nicolas SABY, Véronique ANTONI, Antonio BISPO, Michel BROSSARD, Jean-Luc FORT, Joëlle SAUTER and Chantal GASCUEL2.1. Introduction 352.2. The inventory and monitoring of soils in Europe and in the world 362.3. National mechanisms for the acquisition of soil data 372.3.1. Issues and demands 372.3.2. Structuring of national data collection mechanisms 382.4. Data exploitation for the production of maps and indicators 442.5. Dissemination and availability of data 492.5.1. A national soil information system focused on data dissemination 492.5.2. A progressive enrichment of data and metadata supply 502.5.3. Assisting the use, improvement and control of data 522.6. Conclusion 522.7. Bibliography 53Chapter 3. Soils and Regulation of the Hydrological Cycle 9Marc VOLTZ, Cécile DAGÈS, Laurent PRÉVOT and Ary BRUAND3.1. The soil – facilitator within the hydrological cycle 593.2. Soil control mechanisms 613.2.1. Infiltration–runoff partition 613.2.2. Aquifer recharge 653.2.3. Evaporation and transpiration flows 673.2.4. Capillary rise 703.2.5. Soil water budget 713.2.6. Hydrological flows along hillslopes 723.3. Impacts on the hydrological cycle at soil cover scale 743.3.1. Influence of soil and land use variations 753.3.2. Influence of land use changes 773.3.3. Influence of landscape infrastructures 783.4. Conclusions 79Chapter 4. Soils as Bio-physicochemical Reactors 81Fabienne TROLARD and Guilhem BOURRIÉ4.1. What is a reactor? 814.2. Soil components 854.3. Reactivity drivers 864.4. Main reactions within soils 904.4.1. Master variables: pH and pe 904.4.2. Acid–base reactions 914.4.3. Reactions of oxido-reduction 944.4.4. Degradation of organic matter 954.5. Biogeochemical evolution of the Earth’s surface and the consequences for soils 964.5.1. Availability of chemical elements changed with the Earth’s evolution 964.5.2. The evolution of the Earth’s reactor imposed the evolution of living organisms 994.5.3. Emergence of the “soil” function within the Critical Zone 1014.6. Soil, biogeochemical reactor of soil formation 1034.6.1. Vertical dynamics of soils: the lowering of horizons within landscapes 1054.6.2. Lateral dynamics of soil and transformations of soil covers 1074.6.3. Lateral dynamics by epigenesis (replacement) 1114.7. Soil structure: a case of “soft matter” 1124.8. Bibliography 113Chapter 5. Soils are Biosystems, Habitats and Reserves of Biodiversity 117Jacques BERTHELIN, Éric BLANCHART, Jean TRAP and Jean Charles MUNCH5.1. Introduction 1175.2. Emergence and development of microbial ecology and soil biology 1185.2.1. Discovery of the microbial world, a turning point in the knowledge of the functioning of soil–plant systems 1185.2.2. Discovery of the role of fauna and development of soil biology 1195.3. Soil microbial communities 1195.3.1. Richness and diversity of microbial communities 1195.3.2. Evolution of methodologies in soil microbial ecology 1235.4. Diversity of energy and nutritional pathways of microorganisms, key players in biogeochemical cycles 1245.4.1. Heterotrophy, autotrophy and extreme environments 1245.4.2. Soils, environments where life is active with or without oxygen 1255.5. Richness and diversity of soil fauna 1265.5.1. Diversity of soil fauna 1265.5.2. Classification by size 1275.5.3. Functional classification sensu lato 1275.5.4. Characterization of the fauna 1285.6. Soils, environments with energy and nutritional conditions favorable to microbial life and fauna 1285.7. Determinants and remarkable sites of diversity and soil biological activities 1295.7.1. Parameters and major activity sites 1295.7.2. Impact of land use 1305.7.3. Humus, integrators and developers of specific biological activities 1315.7.4. The rhizosphere, a site of major interactions of soil–plant systems 1325.8. Tools for understanding the habitats of soil organisms 1335.9. Specificities of the soil fauna 1335.9.1. Microregulators 1345.9.2. The communities of organisms called “engineers” 1345.10. Soil organisms: ecosystem service actors 1355.11. Soil quality indicators 1375.11.1. Soil organisms as indicators 1375.11.2. Ecological functions as indicators 1385.12. Conclusion and perspectives 1385.13. Bibliography 139Chapter 6. Soils, a Factor in Plant Production:Agroecosystems 147Claire CHENU, Jean ROGER-ESTRADE, Chantal GASCUEL and Christian WALTER6.1. Introduction 1476.2. Evolution of soil–agriculture relationship over the last few decades 1486.3. Agricultural capability of soils 1506.3.1. How do we define the agricultural capability of a soil? 1506.3.2. Limited soil resources on a global scale 1546.4. Agricultural practices that alter soil properties 1556.5. Toward sustainable management of agricultural soils 1586.6. Conclusion 161Chapter 7. Forest Soils: Characteristics and Sustainability 163Jacques RANGER7.1. Forest soils 1637.2. Bioavailability of nutrients: soil–plant coevolution and the role of the biological cycle 1657.3. Concept of forest soil fertility 1707.4. Specificity of forest soils compared to agricultural soils 1717.5. Threats to forest soils 1757.5.1. Acidification 1757.5.2. Physical degradation 1777.5.3. The particular problem of organic carbon: soil fertility and climate change 1797.5.4. Maintaining biodiversity 1807.5.5. Pollution 1817.5.6. Disappearance of forest soils 1817.6. Conclusions 1817.7. Bibliography 183Chapter 8. Soils and Energy 187Isabelle FEIX8.1. Soils at the heart of global issues 1878.2. Energy context 1888.3. Soils, energy supports and energy suppliers 1908.3.1. Forest and agricultural biomass production: for bioenergy production 1908.3.2. Physical supports of renewable energy: ground-mounted photovoltaic power plants and onshore wind turbines 1908.3.3. Heat and freshness supplies: horizontal superficial geothermal energy and climatic wells 1918.3.4. Peat: formerly used as a biofuel 1918.4. The consequences of energy production on mobilization, occupation and land-use change 1928.4.1. Comparison of land use intensities and land area occupations for energy production 1948.4.2. Comparison of land use changes related to different energies 2028.4.3. Consequences of energy policies for land mobilization and LUC 2048.4.4. Optimization of land use 2068.5. Impacts of energy production on soil loss, degradation and quality 2078.5.1. Impacts common to all energies 2078.5.2. Peat 2088.5.3. Fossil fuels 2088.5.4. Nuclear energy 2088.5.5. Solar and wind energies 2098.5.6. Bioenergies 2108.6. Conclusion 2178.7. Bibliography 219Chapter 9. Soils, Materials, and Infrastructure Supports 233Guilhem BOURRIÉ and Fabienne TROLARD9.1. The use of “raw” soils as building materials 2339.2. Soils, infrastructure supports 2369.3. The classical civil engineering versus the physical approach of granular media 2379.4. Consumption of agricultural land, forest or natural areas by urban sprawl 2399.5. The use of separate particle size fractions 2429.5.1. The use of coarse fractions 2429.5.2. The use of the clay fraction as material and reaction support 2429.5.3. The use of the soil organic fraction 2439.5.4. The use of soil oxides 2439.6. The use of chemical elements after extraction and treatment 2439.7. Bibliography 244Chapter 10. Cultural Dimensions of Soils 247Suzanne MÉRIAUX and Michel-Claude GIRARD10.1. Soil representations – the Earth celebrated 24710.1.1. The written Earth 24810.1.2. The illustrated Earth 25110.1.3. The Earth with sound 25410.2. Humanity, Earth and soil: myths and rites 25810.2.1. Defining myths 25910.2.2. Earth and soils in myths 25910.2.3. Myths 26110.2.4. Rites 26810.2.5. Analogies with the pedological approach? 26910.2.6. Links between humans and earth/soils 27010.2.7. Conclusion 27110.3. Bibliography 272Chapter 11. Environmental and Societal Memories of Soils 275Marie-Agnès COURTY11.1. Ancient soils: archives of human history 27511.1.1. Objectives 27511.1.2. Soil memory and climate change 27611.1.3. Memory of ancient soils and societies 27811.2. Methods of studying soil memory 27911.2.1. The field approach 27911.2.2. Analytical characterization 28111.3. Reading the ancient soil memory 28211.3.1. Foundations 28211.3.2. Sedimentary features 28311.3.3. Combustion features 28511.3.4. Soil features 28711.4. Conclusion and perspectives 29411.5. Bibliography 295Chapter 12. A Mesological Point of View 299Pierre DONADIEU12.1. Soil ubiquity 29912.2. Soil as 30112.3. Off-ground? 30312.4. Living off-ground 30412.5. Limits of the off-ground 30712.6. Conclusion 30912.7. Bibliography 309List of Authors 311Index 315