Headwaters initiate material export to downstream environments. A nested headwater study examined the flux of dissolved constituents and water from a perennial stream and four ephemeral/intermittent streams in the Upper Gulf Coastal Plain of Mississippi. Water was collected during storm and baseflow conditions. Multiple linear regression was used to model constituent concentration and calculate flux. Event was the major source of water discharged from the ephemeral and intermittent streams however, baseflow was the major source for water discharged by the perennial stream during events. The perennial stream had an area weighted average yields of 10.1, 0.01, 1.03, 0.65 kg/ha/yr of DON (dissolved organic nitrogen), NO3 --N, NH4 +-N and PO4 -3, respectively while large variabilities existed between the ephemeral and intermittent streams. These findings highlight the importance of headwaters in protecting the low order drainage basins as a key to water quality within perennial streams.

Abstract
 1. Introduction
 2. Materials and methods
  2.1. Site description
  2.2. Streamwater sampling
  2.3. Laboratory analysis
  2.4. Data analysis
 3. Results
  3.1. Hydrometric observations
  3.2. Flux of dissolved constituents
 4. Discussion
 5. Conclusion
 References

• Byoung-Koo Choi(Research Center for River Flow Impingement and Debris Flow, Gangneung-Wonju National University) Corresponding author
• Clay N. Mangum(Department of Forestry, Mississippi State University)
• Jeffery A. Hatten(Department of Forest Engineering, Resources & Management, Oregon State University)
• Janet C. Dewey(Department of Geology and Geophysics, University of Wyoming)
• Ying Ouyang(USDA Forest Service)