Book contents
- Frontmatter
- Contents
- List of Contributors
- Preface
- Editorial Acknowledgements
- 1 Soil carbon relations: an overview
- 2 Field measurements of soil respiration: principles and constraints, potentials and limitations of different methods
- 3 Experimental design: scaling up in time and space, and its statistical considerations
- 4 Determination of soil carbon stocks and changes
- 5 Litter decomposition: concepts, methods and future perspectives
- 6 Characterization of soil organic matter
- 7 Respiration from roots and the mycorrhizosphere
- 8 Separating autotrophic and heterotrophic components of soil respiration: lessons learned from trenching and related root-exclusion experiments
- 9 Measuring soil microbial parameters relevant for soil carbon fluxes
- 10 Trophic interactions and their implications for soil carbon fluxes
- 11 Semi-empirical modelling of the response of soil respiration to environmental factors in laboratory and field conditions
- 12 Modelling soil carbon dynamics
- 13 The role of soils in the Kyoto Protocol
- 14 Synthesis: emerging issues and challenges for an integrated understanding of soil carbon fluxes
- 15 Appendix: Towards a standardized protocol for the measurement of soil CO2 efflux
- Index
- References
4 - Determination of soil carbon stocks and changes
Published online by Cambridge University Press: 11 May 2010
- Frontmatter
- Contents
- List of Contributors
- Preface
- Editorial Acknowledgements
- 1 Soil carbon relations: an overview
- 2 Field measurements of soil respiration: principles and constraints, potentials and limitations of different methods
- 3 Experimental design: scaling up in time and space, and its statistical considerations
- 4 Determination of soil carbon stocks and changes
- 5 Litter decomposition: concepts, methods and future perspectives
- 6 Characterization of soil organic matter
- 7 Respiration from roots and the mycorrhizosphere
- 8 Separating autotrophic and heterotrophic components of soil respiration: lessons learned from trenching and related root-exclusion experiments
- 9 Measuring soil microbial parameters relevant for soil carbon fluxes
- 10 Trophic interactions and their implications for soil carbon fluxes
- 11 Semi-empirical modelling of the response of soil respiration to environmental factors in laboratory and field conditions
- 12 Modelling soil carbon dynamics
- 13 The role of soils in the Kyoto Protocol
- 14 Synthesis: emerging issues and challenges for an integrated understanding of soil carbon fluxes
- 15 Appendix: Towards a standardized protocol for the measurement of soil CO2 efflux
- Index
- References
Summary
INTRODUCTION
Soil carbon pools and the global carbon cycle
In terrestrial ecosystems soils represent the major reservoir of organic carbon (Table 4.1), but with large and yet unquantified uncertainties in their estimates (mainly due to low soil sample numbers used for global up-scaling and assumptions on mean soil depths). At the global level, the soil organic matter (SOM) pool (estimated to 1 m depth) contains about 1580 Pg of carbon (Pg = 1015 g), about 610 Pg are stored in the vegetation and about 750 Pg are present in the atmosphere (Schimel, 1995). Carbon is found in soils both in organic and inorganic forms (Table 4.2). Organic carbon is commonly classified into three ‘arbitrary’ pools, mostly for modelling purposes (such as in CENTURY), i.e. fast, slow and passive reflecting the rate of turnover. However, it is difficult to relate these pools to soil carbon fractions (see Section 4.1.5). The total amount of carbonate carbon to 1 m depth is estimated at 695–748 Pg carbon (Batjes, 1996). About one third of organic soil carbon occurs in forests and another third in grasslands and savannas, the rest in wetlands, croplands and other biomes (Janzen, 2004). The global soil organic carbon map (Fig. 4.1, ISLSCP II; ORNL DAAC, http://daac.ornl.gov/) shows the areas of high soil organic carbon predominantly in cold boreal (e.g. Northern Canada) and warm and humid tropical regions (e.g. South-East Asia), reflecting areas of deep organic soils (i.e. peatlands).
- Type
- Chapter
- Information
- Soil Carbon DynamicsAn Integrated Methodology, pp. 49 - 75Publisher: Cambridge University PressPrint publication year: 2010
References
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