Biogeochemistry of the Critical Zone

Series Editor’s Preface
Contents
1 An Introduction to Biogeochemistry of the Critical Zone
	References
2 Hot Spots and Hot Moments in the Critical Zone: Identification of and Incorporation into Reactive Transport Models
	2.1 Introduction
		2.1.1 Definition of Terms
		2.1.2 Scope and Overall Impact
	2.2 Capturing Scales and Complexity Using Models
		2.2.1 Hot Spots Within the Hyporheic Zone—The Redox Microzone Concept
		2.2.2 HSHMs at the Floodplain Scale
		2.2.3 HSHMs Along River Corridors
	2.3 Current Understanding and the Path Forward
		2.3.1 A Conceptual Take on HSHMs Using a Trait-Based Framework
		2.3.2 Improvements in Field-Scale Characterization of Hyporheic Zones
		2.3.3 Recent Developments in Observation and Modeling of Hot Spots Featuring the Sediment Water Interface
	2.4 How Can Models Contribute?
		2.4.1 Scale Aware Modeling/Parameterization
		2.4.2 A Preemptive Prioritization of HSHMs
	2.5 Concluding Remarks
	References
3 Constraints of Climate and Age on Soil Development in Hawai‘i
	3.1 Understanding Critical Zone Functioning Through State Factor Analysis
	3.2 Physiographic Setting
	3.3 Analytical Approach
	3.4 Development of Critical Zone Properties Across the Hawaiian Islands
		3.4.1 Weathering Depth and Chemical Denudation
		3.4.2 Conditioning Lava Flows for Critical Zone Development
	3.5 Biogeochemical Properties of Hawaiian Critical Zone
		3.5.1 Weathering and Soil Properties
	3.6 Soil Process Domains and Pedogenic Thresholds in Hawai‘i
		3.6.1 Process Domains
		3.6.2 Transitions Among Process Domains
	3.7 Conclusions
	References
4 Biofilms in the Critical Zone: Distribution and Mediation of Processes
	4.1 Introduction
	4.2 Documenting Environmental Biofilms Using the Scanning Electron Microscope
	4.3 Biofilms in the Critical Zone
		4.3.1 Plant Hosted, Biofilms Above Ground: Phyllosphere and Endosphere
		4.3.2 Biofilms in the Soil
		4.3.3 Biofilms in the Deep Critical Zone
	4.4 Biofilm Mediation of Critical Zone Processes
		4.4.1 Biofilm Role in OM Stabilization, Biogenic Minerals
		4.4.2 Biofilm Role in Mineral Weathering
		4.4.3 Biofilm Strategies to Survive Drought
	4.5 Summary
	References
5 Eroded Critical Zone Carbon and Where to Find It: Examples from the IML-CZO
	5.1 Introduction
		5.1.1 Field Site
	5.2 Methods
		5.2.1 Estimates of Post-settlement Sediment Accumulation
		5.2.2 Organic Carbon Concentrations and C-Isotopic Compositions
		5.2.3 Biomarkers
	5.3 Results and Discussion
		5.3.1 Sediment and OC Inventories
		5.3.2 Organic C Sources and Composition
	5.4 Conclusions
	References
6 Advances in Biogeochemical Modeling for Intensively Managed Landscapes
	6.1 Introduction
	6.2 Long-Term Carbon Dynamics
	6.3 Event-Scale Biogeochemical Dynamics: The Impact  of Microtopography and Artificial Drainage
	6.4 Root Zone Biogeochemistry
	References
7 Hillslope Position and Land-Use History Influence P Distribution in the Critical Zone
	7.1 Introduction
		7.1.1 Effect of Ecosystem Development on P Distribution
		7.1.2 Effect of Topography on P Distribution
		7.1.3 Effect of Land Use on P Distribution
		7.1.4 Topography and Land Use in the Calhoun CZO
	7.2 Methods
		7.2.1 Study Site
		7.2.2 Sample Collection
		7.2.3 Sample Analyses
		7.2.4 Data Analyses
	7.3 Results
		7.3.1 Soil Analyses
		7.3.2 Soil Solution Analyses
		7.3.3 Resin Capsule Analyses
		7.3.4 Stream Analyses
	7.4 Discussion
		7.4.1 Hillslope Effects
		7.4.2 Effects of Land Use on Vertical Leaching
		7.4.3 Soil Solution P
		7.4.4 Effects of Land-Use History on P Fractions
	7.5 Conclusion
	References