1 / 35

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. Brian Lutz PhD Candidate, Duke University Visiting Researcher, University of Oslo. Outline. Research Background and Justification

lbraun
Download Presentation

Brian Lutz PhD Candidate, Duke University Visiting Researcher, University of Oslo

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Investigating interactions between the major biogeochemical cycles through understanding ecosystem-scale organic matter dynamics Brian Lutz PhD Candidate, Duke University Visiting Researcher, University of Oslo

  2. 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

  3. Human Domination of the Global N Cycle Credits: Netherlands Environmental Assessment Agency, www.pbl.nl

  4. Nitrogen Saturation: Environmental Consequences Credits: Diaz and Rosenberg, Science, 2008

  5. Nitrogen Saturation: Symptoms and Diagnosis Credits: Aber, BioScience, 1998

  6. What about organic nitrogen? Credits: Bormann et al., Science, 1977

  7. What about organic nitrogen? Organic N turnover supports the majority of ecosystem production in most ecosystems Credits: Bormann et al., Science, 1977

  8. DON Losses from the landscape are important Credits: Scott et al., Global BGC Cycles, 2007

  9. Nitrogen Saturation: Symptoms and Diagnosis DON?? Credits: Aber, BioScience, 1998

  10. ‘Breaks in the Cycle’: Increased organic N losses? - Neff et al., Frontiers in Ecology, 2003 Saturated Plant Demand Anthropogenic N Additions INCREASED ORGANIC N LOSSES

  11. DON Release Hypothesis: Schematic

  12. DON Release Hypothesis: Predictions [DON] DON [DIN]

  13. 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

  14. DON Release Hypothesis: Preliminary Test

  15. DON Release Hypothesis: Preliminary Test

  16. DON Release Hypothesis: Preliminary Test

  17. DON Release Hypothesis: Preliminary Test

  18. DON Release Hypothesis: Preliminary Test

  19. DON Release Hypothesis: Preliminary Test Bioavailability Assays +C +N +CN +DI

  20. Indirect Carbon Control Hypothesis

  21. 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

  22. Ecosystem Scale Experimental Manipulations NUTRIENT SPIRALING THEORY

  23. Ecosystem Scale Experimental Manipulations NUTRIENT SPIRALING THEORY Pump Metering in C/N

  24. Ecosystem Scale Experimental Manipulations Day 2: C Enrichment Day 1: N Enrichment

  25. 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

  26. The Importance of Geochemical Controls

  27. Large differences in DOM stoichiometry with different parent geology

  28. Batch incubation soil sorption assays Unprocessed Soil Removal of Fe/Al Removal of Native Organic Matter Artificial Leachates

  29. Batch incubation soil sorption assays Credits: Qualls, Forest Ecol. & Managmnt, 2001

  30. 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

  31. DOM Characterization: Fluorescence and PARAFAC

  32. 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

  33. 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

  34. Acknowledgments • Host: • Rolf Vogt • UiO Chemistry Department • Funding: • Research Council of Norway • National Science Foundation

  35. Implications for Ecosystem N Losses Credits: Schimel and Bennett, Ecology, 2004

More Related