2. Ecosystem services
2.1. Ecosystem service classification schemes
2.2. Earth's Critical Zone
2.3. SoilTrEC
2.4. Soil and Earth's Critical Zone
3. Frameworks for soil ES
4. Soil ES and economic valuation studies
4.1. Value in economics
4.2. Valuation tools
4.3. Valuing soil ES: reviewing values from the literature
4.3.1. Support functions
4.3.2. Regulating services
4.3.3. Provisioning services
4.3.4. Cultural services
4.4. Summary
5. Concluding discussion
Acknowledgements
Appendix A
References