xiv
Contents
Estimating the Vegetative Component of Ecosystem Water Fluxes
207
Sap Flow Measurements
208
Whole Root/Shoot Hydraulic Conductance
209
Summary
210
References
211
14 Nutrient Transformations
215
John M. Stark
Introduction
215
Non-Isotope Methods
217
Net Rate Measurements with Inhibitors
217
Rate Measurements Obtained from Nutrient Budgets
221
Net Rate Measurements with "Super Sinks"
221
Rate Measurements Using Substrate Analogs
222
Isotope Methods
223
Tracer Measurements
223
Isotope Dilution Measurements
224
Estimation of Rates by Modeling Methods
229
Natural Abundance Isotope Methods
230
Application of Methods to Other Nutrient Transformations
231
References
231
15 Biogenic Trace Gas Exchanges
235
Pamela Matson and Allen Goldstein
Approaches for Estimation of Fluxes
235
Enclosure Methods
236
Micrometeorological Approaches
242
Analytical Methods for Trace Gases
242
Multiple Approaches for Understanding and Estimating Fluxes
244
References
244
16 Ecosystem Nutrient Balance and Dynamics
249
Kate Lajtha
Introduction
249
Input-Output Ecosystem Budgets at the Watershed Scale
250
Atmospheric Inputs
251
Stream Outputs
252
Other Budget Approaches
253
Stand-Level Budgets Using Lysimetry
253
Monolith Lysimetry and Sandbox Experiments
256
Nitrogen-15 Studies at the Ecosystem Scale
258
References
259
17 Deposition of Nutrients and Pollutants to Ecosystems
265
Lars O. Hedin
Role of Atmospheric Deposition
265
Vectors of Delivery
266
Scales of Inquiry
266