Contents
6 Benthic Respiration in Aquatic Sediments
Eo Thamdrup and Donald E. Canfield
Introduction
86
86
Total Benthic Mineralization, Flux Measurements
88
Other Total Mineralization Assays
89
Respiratory Pathways, Oxygen Respiration
90
Nitrate Reduction
91
Manganese and Iron Reduction
92
Sulfate Reduction
95
Methanogenesis
96
Conclusions
97
References
97
7 Decomposition and Soil Organic Matter Dynamics
104
G. Philip Robertson and Eldor A. Paul
Introduction
104
Plant Litter Decomposition
106
Fine Litter Decomposition Rates
106
Woody Detritus
109
Reciprocal Transplants and Standard Substrates
109
Soil Organic Matter Dynamics
110
Soil Organic Matter Stores
110
Physical Fractionation of Soil Organic Matter
110
Biological Soil Organic Matter Fractions
111
Use of Tracers
113
References
113
8 Stable Isotope Tracers and Mathematical Models in Soil Organic
Matter Studies
117
Ronald Amundson and W. Troy Baisden
Introduction
117
Soil Organic Matter Pools and Dynamics
117
SOM Pools
117
SOM Additions
118
SOM Losses
118
Internal SOM Transfers
119
SOM Transformations
119
Stable Carbon Isotopes in Organic Matter
119
Well-Mixed One Box Model of C Isotopes in SOM
119
Uses of Well-Mixed Box Models in SOM C Studies
122
Models for Vertical Variations in the Ol3C Value of SOM
123
Stable Nitrogen Isotopes in Organic Matter
128
Well-Mixed One Box Soil Ecosystem Model of N Isotopes
129
Use of N Isotopes in SOM as a Tracer
132
Model of Vertical Variations in 015N Value of SOM
132
Conclusions
134
References
134
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