brian lutz phd candidate, duke university visiting researcher, university of oslo investigating...
TRANSCRIPT
Brian Lutz
PhD Candidate, Duke University
Visiting Researcher, University of Oslo
Investigating interactions between the major biogeochemical cycles
through understanding ecosystem-scale organic matter dynamics
Outline
Research Background and Justification Ch 1: Preliminary Test of Hypotheses
Synoptic Surveys of Stream Chemistry Ch 2: Ecosystem Scale Manipulations
Stream Nutrient Spiraling Ch 3: Geochemical Controls on DON Losses
Soil Sorption Assays Ch 4: DOM Characterization
Fluorescence and PARAFAC Modeling Eutropia Project
Human Domination of the Global N Cycle
Credits: Netherlands Environmental Assessment Agency, www.pbl.nl
Nitrogen Saturation: Environmental Consequences
Credits: Diaz and Rosenberg, Science, 2008
Nitrogen Saturation: Symptoms and Diagnosis
Credits: Aber, BioScience, 1998
What about organic nitrogen?
1%
99%
Inorganic NOrganic N
Credits: Bormann et al., Science, 1977
What about organic nitrogen?
1%
99%
Inorganic NOrganic N
Credits: Bormann et al., Science, 1977
Organic N turnover supports the majority of ecosystem production in most ecosystems
DON Losses from the landscape are important
Credits: Scott et al., Global BGC Cycles, 2007
Nitrogen Saturation: Symptoms and Diagnosis
Credits: Aber, BioScience, 1998
DON??
‘Breaks in the Cycle’: Increased organic N losses?
Anthropogenic N Additions
Saturated Plant Demand
INCREASED ORGANIC N LOSSES
- Neff et al., Frontiers in Ecology, 2003
DON Release Hypothesis: Schematic
DON Release Hypothesis: Predictions
DON
[DIN]
[DO
N]
Outline
Research Background and Justification Ch 1: Preliminary Test of Hypotheses
Synoptic Surveys of Stream Chemistry Ch 2: Ecosystem Scale Manipulations
Stream Nutrient Spiraling Ch 3: Geochemical Controls on DON Losses
Soil Sorption Assays Ch 4: DOM Characterization
Fluorescence and PARAFAC Modeling Eutropia Project
DON Release Hypothesis: Preliminary Test
DON Release Hypothesis: Preliminary Test
DON Release Hypothesis: Preliminary Test
DON Release Hypothesis: Preliminary Test
DON Release Hypothesis: Preliminary Test
DON Release Hypothesis: Preliminary Test
+C +N +CN +DI
Bioavailability Assays
Indirect Carbon Control Hypothesis
Outline
Research Background and Justification Ch 1: Preliminary Test of Hypotheses
Synoptic Surveys of Stream Chemistry Ch 2: Ecosystem Scale C/N Manipulations
Stream Nutrient Spiraling Ch 3: Geochemical Controls on DON Losses
Soil Sorption Assays Ch 4: DOM Characterization
Fluorescence and PARAFAC Modeling Eutropia Project
Ecosystem Scale Experimental ManipulationsNUTRIENT SPIRALING THEORY
Ecosystem Scale Experimental ManipulationsNUTRIENT SPIRALING THEORY
Pump Metering in
C/N
Ecosystem Scale Experimental Manipulations
Day 1: N Enrichment Day 2: C Enrichment
Outline
Research Background and Justification Ch 1: Preliminary Test of Hypotheses
Synoptic Surveys of Stream Chemistry Ch 2: Ecosystem Scale Manipulations
Stream Nutrient Spiraling Ch 3: Geochemical Controls on DON Losses
Soil Sorption Assays Ch 4: DOM Characterization
Fluorescence and PARAFAC Modeling Eutropia Project
The Importance of Geochemical Controls
Large differences in DOM stoichiometry with different parent geology
143.4
36.6
0
20
40
60
80
100
120
140
160
180
200
Dolomite Shale
Parent Mineralogy
DO
M C
:N
Batch incubation soil sorption assays
Removal of Fe/Al
Unprocessed Soil
Removal of Native Organic Matter
Artificial Leachates
Batch incubation soil sorption assays
Credits: Qualls, Forest Ecol. & Managmnt, 2001
Outline
Research Background and Justification Ch 1: Preliminary Test of Hypotheses
Synoptic Surveys of Stream Chemistry Ch 2: Ecosystem Scale Manipulations
Stream Nutrient Spiraling Ch 3: Geochemical Controls on DON Losses
Soil Sorption Assays Ch 4: DOM Characterization
Fluorescence and PARAFAC Modeling Eutropia Project
DOM Characterization: Fluorescence and PARAFAC
Outline
Research Background and Justification Ch 1: Preliminary Test of Hypotheses
Synoptic Surveys of Stream Chemistry Ch 2: Ecosystem Scale Manipulations
Stream Nutrient Spiraling Ch 3: Geochemical Controls on DON Losses
Soil Sorption Assays Ch 4: DOM Characterization
Fluorescence and PARAFAC Modeling Eutropia Project
What am I doing in Norway?
Working with Eutropia Project Flux of Organic N and P from catchment soils to stream Event (storm) export of OM from catchments End Member Mixing Models (EMMA)
X
Y
Z
Acknowledgments
Host: Rolf Vogt UiO Chemistry Department
Funding: Research Council of Norway National Science Foundation
Implications for Ecosystem N Losses
Credits: Schimel and Bennett, Ecology, 2004