1. The impact of fire on hydrology and suspended sediment and nutrient export in southern California chaparral watersheds Santa Barbara Coastal Long Term Ecological Research (SBC LTER) Santa Barbara Coastal Long Term Ecological Research (SBC LTER) Masters Research Seminar By J. Scott Coombs

2. Talk Outline  Introduction  Methods  Hydrology  Suspended Sediment Export  Nutrient Biogeochemistry  Nutrient Export  Summary of Results  Acknowledgments  Questions February 23, 2005

3. Gaviota Wildfire: June 5 to 12, 2004

4. Historical Fires in Study Area

5. San Onofre Creek February19, 2005 Stream Sampling

6. Stream Gauging

9. Changes to Hydrologic Response:  Infiltration decreases  formation of hydrophobic soil layer  compaction of soil  Evapotranspiration and Interception decrease  more rainfall is available for runoff

10. Early Season Storm Hydrographs

11. Mid-Winter Storm Hydrographs

12. San Onofre Creek December 28, 2004 November 15, 2004 October 26, 2004October 19, 2004

13. San Onofre Creek February19, 2005 February 22, 2005 April 27, 2005 January 7, 2005 January 26, 2005

14. Discharge Patterns

15. Changes to Sediment Export:  Infiltration decreases  Runoff and peak discharge increase  Interception decreases due to vegetation loss

16. Discharge-Suspended Sediment Trends

17. Gaviota Watershed

18. Sediment Deposition in Gaviota: November 22,2004 Sediment Deposition in Gaviota: November 22,2004

19. Discharge-Suspended Sediment Trends

20. Sediment movement in San Onofre: Photos taken May 2005

21. Discharge-Suspended Sediment Trends

22. Suspended Sediment Storm Export

23. Nitrogen Biogeochemistry

25. Dissolved Nitrogen Response

26. Nitrate Storm Export

27. DON Storm Export

28. Changes in Phosphate Export  Phosphate is rapidly mineralized and deposited on soil surface but is not as mobile as nitrate  Increases in phosphate concentration in runoff roughly correlates with peak discharge

29. Phosphate Storm Export

30. Summary of Results Hydrology Hydrologic response was typical for southern California chaparral during early season storms but differences decreased as the season progressed with above average rainfall. Hydrologic response was typical for southern California chaparral during early season storms but differences decreased as the season progressed with above average rainfall. Suspended Sediment 10-fold increase in suspended sediment export 10-fold increase in suspended sediment exportNutrients 30 times increase in ammonium export 30 times increase in ammonium export 5.5 times increase in nitrate export 5.5 times increase in nitrate export 2.8 times increase in DON export 2.8 times increase in DON export 2 times increase in phosphate export 2 times increase in phosphate export

31. Acknowledgements Special thanks to My advisors: John Melack, Arturo Keller, and Jordan Clark. My advisors: John Melack, Arturo Keller, and Jordan Clark. Frank Setaro and Allen Doyle for their assistance in sample processing and analysis. Frank Setaro and Allen Doyle for their assistance in sample processing and analysis. Tim Robinson and Al Leydecker for their advice and solace. Tim Robinson and Al Leydecker for their advice and solace. My family and friends for their support and encouragement. My family and friends for their support and encouragement. My wife, Maria, for her love and understanding of my absence on all those rainy nights. My wife, Maria, for her love and understanding of my absence on all those rainy nights.

32. Questions?