Note: Cover -- Half-title -- Title -- Copyright -- Contents -- Contributors -- Preface -- 1 Soil carbon relations: an overview -- 1.1 INTRODUCTION -- 1.2 SOIL CARBON RELATIONS: A BASIC CONCEPT -- 1.3 RESEARCH LINES -- 1.3.1 Soil chemistry -- 1.3.2 Physical mechanisms -- 1.3.3 The physiological research line -- 1.3.4 The ecological research line -- 1.4 CURRENT CHALLENGES -- 1.4.1 Experimental design of flux measurements and stock taking: limitations at the plot scale -- 1.4.2 Litter and soil organic matter: a meaningful separation and characterization of carbon pools -- 1.4.3 Measuring autotrophic versus heterotrophic fluxes: available methods and their meaning -- 1.4.4 Soil microbes, soil fauna and trophic interactions: describing communities, their functions and activity -- 1.4.5 Temperature sensitivity and acclimation: application and shortfalls of different concepts -- 1.4.6 Modelling soil carbon dynamics: current and future model validation and structures -- 1.4.7 The role of soils in a changing climate: towards a better understanding of the role of soils in the greenhouse gas budget -- 1.5 SUMMARY -- REFERENCES -- 2 Field measurements of soil respiration: principles and constraints, potentials and limitations of different methods -- 2.1 INTRODUCTION -- 2.2 MEASUREMENT PRINCIPLES AND HISTORY OF TECHNICAL DEVELOPMENTS -- 2.3 DISTURBANCES INTRODUCED BY THE MEASUREMENT SYSTEM -- 2.3.1 Vertical pressure gradient -- 2.3.2 Vertical CO2 concentration gradient -- 2.3.3 Horizontal wind -- 2.3.4 Other effects -- 2.4 COMPARISON OF THE EXISTING SYSTEMS AND RECOMMENDATIONS -- 2.5 EXPERIMENTAL DESIGN -- REFERENCES -- 3 Experimental design: scaling up in time and space, and its statistical considerations -- 3.1 INTRODUCTION -- 3.2 SPATIAL AND TEMPORAL VARIABILITY -- 3.2.1 Sources of variability -- 3.2.2 Coping with variability -- 3.2.2.1 Spatial variability. , 3.2.2.2 Temporal variability -- 3.2.2.3 Implications for soil CO2 efflux sampling strategies -- 3.2.3 Laboratory measurements -- 3.2.4 Scaling up -- 3.2.5 Site variation: random, stratified or systematic design, and avoiding bias -- 3.2.6 Using geographical information systems (mapping and querying) -- 3.3 FORMULATING AND TESTING HYPOTHESES -- 3.3.1 Make the observation -- 3.3.2 Formulate the hypothesis -- 3.3.3 Draw the graph -- 3.3.4 Design and perform the experiment -- 3.3.5 Evaluate the data with the appropriate statistical design -- 3.4 CONCLUSION -- REFERENCES -- 4 Determination of soil carbon stocks and changes -- 4.1 INTRODUCTION -- 4.1.1 Soil carbon pools and the global carbon cycle -- 4.1.2 Definition of soil organic carbon (SOC) and soil organic matter (SOM) -- 4.1.3 The soil carbon balance -- 4.1.4 Effects of fire in altering the reservoirs of soil carbon -- 4.1.5 Factors determining soil organic carbon turnover -- 4.1.6 Soil organic carbon stocks and climate change -- 4.2 METHODS FOR THE DETERMINATION OF SOIL ORGANIC CARBON CHANGES -- 4.2.1 The flux approach -- 4.2.2 The repeated inventory approach -- 4.2.3 Examining changes in specific fractions of carbon -- 4.2.4 Soil sampling, preparation and analysis -- 4.2.4.1 Soil sampling -- 4.2.4.2 Sample treatment and preparation -- 4.2.4.3 Soil carbon analyses -- 4.2.4.4 Bulk density and stone content -- 4.2.4.5 Root content -- 4.3 CONSIDERATIONS FOR SOIL CARBON MONITORING SCHEMES -- 4.4 UP-SCALING AND THE ROLE OF MODELS FOR DETECTING SOIL ORGANIC CARBON CHANGES -- 4.5 SOIL CARBON STOCK CHANGES: SOME PRACTICAL EXAMPLES -- 4.6 CONCLUSIONS -- REFERENCES -- 5 Litter decomposition: concepts, methods and future perspectives -- 5.1 LITTER DECOMPOSITION CONCEPT -- 5.2 KNOWLEDGE OF LITTER DECOMPOSITION AND ITS CONTROLLING FACTORS -- 5.3 MEASURING LITTER DECAY. , 5.4 LITTER BAG STUDIES TO QUANTIFY STANDING LITTER TURNOVER TIMES: HOW DO WE DEAL WITH THE ASYMPTOTIC VALUE? -- 5.5 MODELLING LITTER DECAY -- 5.6 EMERGING ISSUES -- 5.6.1 Interaction and feedback between root activity and litter decay -- 5.6.2 Incorporation of above-ground litter-derived carbon to SOM -- 5.6.3 Functional role of soil microbes: does the fungal-to-bacteria ratio affect carbon flow from litter to recalcitrant SOM? -- 5.7 CUTTING-EDGE METHODOLOGIES -- ACKNOWLEDGEMENTS -- REFERENCES -- 6 Characterization of soil organic matter -- 6.1 INTRODUCTION -- 6.2 OVERVIEW OF TECHNIQUES TO FRACTIONATE AND CHARACTERIZE SOIL ORGANIC MATTER -- 6.2.1 Soil organic matter fractionation -- 6.2.1.1 Biological fractionation -- 6.2.1.2 Physical fractionation -- 6.2.1.3 Chemical fractionation -- 6.2.1.4 Black carbon fractionation and quantification -- 6.2.2 Soil organic matter characterization -- 6.2.2.1 Compound-specific characterization -- 6.2.2.2 Whole-soil SOM characterization -- 6.3 SHORTCOMINGS -- 6.3.1 The remaining gap between SOM fractionation and characterization -- 6.3.2 The current fractionation methodologies frequently isolate non-uniform SOM pools with different turnover times -- 6.3.3 Biochemical characteristics of SOM have seldom been directly linked to microbial functioning and resulting SOM dynamics -- 6.3.4 The relationship between the dynamics of specific SOM fractions and the dynamics of whole SOM has not often been considered -- 6.3.5 Isolated single compounds or compound classes often represent such a small proportion of the total SOM content that the quantification or modelling of their dynamics may have little relation to the dynamics of SOM as a whole -- 6.4 DIRECTIONS FOR FUTURE RESEARCH AND PROMISING NEW TECHNIQUES -- 6.4.1 Quantification of the turnover of different SOM fractions by isotope analysis. , 6.4.2 Relating SOM quality and dynamics to microbial functioning -- 6.4.3 Exploration of new avenues to characterize whole-soil and fraction SOM quality -- 6.5 CONCLUSIONS -- REFERENCES -- 7 Respiration from roots and the mycorrhizosphere -- 7.1 INTRODUCTION -- 7.2 ROOT AND MYCORRHIZOSPHERE RESPIRATION -- 7.2.1 Eco-physiology of root respiration -- 7.2.2 Regulation of root respiration by plant and environmental factors -- 7.2.2.1 Temperature -- 7.2.2.2 Moisture -- 7.2.2.3 Nutrients -- 7.2.2.4 Insolation and carbohydrate supply -- 7.2.2.5 Soil and atmospheric CO2 concentrations -- 7.2.2.6 Root morphology and plant age -- 7.2.3 Rhizomicrobial and mycorrhizal respiration -- 7.2.3.1 Rhizomicrobial respiration -- 7.2.3.2 Mycorrhizal respiration -- 7.3 MEASURING ROOT AND MYCORRHIZOSPHERE RESPIRATION -- 7.3.1 General considerations -- 7.3.1.1 Field vs. laboratory measurements: which method to use -- 7.3.1.2 Expressing respiration rates -- 7.3.1.3 Measuring root respiration temperature response -- 7.3.2 Field methods -- 7.3.2.1 Excision methods -- 7.3.2.2 Intact-root chamber methods -- 7.3.2.3 Measurement techniques for respiration of large coarse roots -- 7.3.2.4 Mesh exclusion method -- 7.3.2.5 Field measurements to take in conjunction with root respiration -- 7.3.3 Laboratory methods -- 7.3.3.1 O2 consumption and CO2 release methods -- 7.3.3.2 Measuring root respiration temperature response in the laboratory -- 7.3.4 Calculating the Q10 -- 7.3.4.1 Fitting curves to measured data -- 7.3.4.2 Predicting respiration in the absence of a measured temperature response -- 7.3.5 Methodology for quantifying the degree of acclimation -- 7.3.5.1 Set temperature method -- 7.3.5.2 Homeostasis-based methods -- 7.3.5.3 Quantifying acclimation: which method to use? -- 7.4 MYCORRHIZOSPHERE RESPIRATION AT THE ECOSYSTEM SCALE -- 7.5 CONCLUDING REMARKS -- REFERENCES. , 8 Separating autotrophic and heterotrophic components of soil respiration: lessons learned from trenching and related root-exclusion experiments -- 8.1 INTRODUCTION -- 8.2 ROOT EXCLUSION: THE TRENCHING APPROACH -- 8.2.1 Calculations and assumptions -- 8.2.2 Limitations and shortcomings -- 8.3 ROOT EXCLUSION: OTHER RELATED APPROACHES -- 8.3.1 Artificial gaps -- 8.3.2 Girdling experiments -- 8.3.3 Clipping experiments -- 8.4 LESSONS LEARNED FROM ROOT EXCLUSION EXPERIMENTS -- 8.4.1 Seasonal variation in partitioning -- 8.4.2 Site to site variations in partitioning -- 8.4.3 Age effects on partitioning -- 8.4.4 Global aspects of partitioning -- 8.5 CONCLUDING REMARKS -- ACKNOWLEDGEMENTS -- REFERENCES -- 9 Measuring soil microbial parameters relevant for soil carbon fluxes -- 9.1 INTRODUCTION -- 9.2 METHODS FOR ECO-PHYSIOLOGICAL CHARACTERIZATION OF SOIL MICROBIOTA -- 9.2.1 Biomass -- 9.2.2 Ratios of different microbial biomass estimates -- 9.2.3 Basal respiration and metabolic quotients -- 9.2.4 Community oriented approaches -- 9.2.5 Extracellular enzyme activities -- 9.2.6 Specific substrate use -- 9.2.7 Tracers -- 9.2.8 Stable isotope probing -- 9.3 MICROBIAL ACCLIMATION AND STRESS RESPONSE -- 9.3.1 Microbial acclimation to climate and stress by climatic factors -- 9.3.2 Microbial acclimation to chemical soil properties -- 9.3.3 Plant-microbe interactions -- 9.4 INTEGRATION AND THE USE OF MICROBIOLOGICAL INFORMATION IN MODELLING SOIL CARBON DYNAMICS -- 9.4.1 The need for different scales and scale transition -- 9.4.2 Modelling -- 9.5 CONCLUSIONS -- REFERENCES -- 10 Trophic interactions and their implications for soil carbon fluxes -- 10.1 INTRODUCTION -- 10.2 ABOVE- AND BELOW-GROUND HERBIVORY -- 10.2.1 Short-term responses to herbivores -- 10.2.1.1 Animal waste products and soil carbon dynamics. , 10.2.1.2 Herbivore-induced changes in litter chemistry and soil carbon dynamics.