, Volume 32, Issue 2, pp 301–310 | Cite as

Landscape and Wetland Influences on Headwater Stream Chemistry in the Kenai Lowlands, Alaska

  • Coowe M. WalkerEmail author
  • Ryan S. King
  • Dennis F. Whigham
  • Steven J. Baird


Headwater streams are typically closely connected with the surrounding watershed landscape, making them sensitive to local watershed conditions. Headwater streams of the Kenai Lowlands in Alaska provide important rearing habitat for juvenile salmon and other biota, and understanding the connections between surrounding landscapes and stream conditions will improve management capabilities. We conducted field evaluations of 30 headwater stream sites on the Kenai Lowlands of Alaska, stratified across watersheds and wetland types, and combined these results with GIS analysis of 12 landscape metrics. Flow-weighted slope (FWS), which is an indicator of the combined influence of percentage cover and topographic position of wetlands, was the best predictor of stream chemistry. Our results revealed distinct differences in water chemistry among headwaters that are largely driven by topography and the amount of wetland in the upstream drainage area. Streams with a high FWS (higher gradient, low wetness) had higher dissolved oxygen and dissolved inorganic nitrogen (mostly nitrate-N), and lower temperatures. Lower FWS streams (low gradient, high wetness) had higher dissolved organic carbon, temperatures, and ammonium and lower dissolved oxygen, all of which were consistent with strong connections between wetlands in watershed and headwater streams. The flow-weighted slope metric is a landscape feature that can be easily derived from GIS, and can be used as a spatially explicit approach for predicting landscape connections to headwater streams on the Kenai Lowlands.


Watersheds Peatlands Headwater streams Nutrients Water chemistry Topographic wetness index Kenai Peninsula Alaska 



This project was funded by a grant from the US EPA grant number CD-96011801-0, and through additional support through Baylor University, the Kachemak Bay Research Reserve and the Smithsonian Environmental Research Center. Many people assisted with the rigorous field work necessary to collect the field data for this project including Amy Alderfer, Jennifer Brewer, Shan Burson, Kim Cooney, Patrick Dougherty, Dwayne Evans, Rachel Hovel, Megan Murphy, Caitlin Schott, Simeon Smith, and Scott Thompson. We appreciate and thank Kathy Boomer, Jay O’Neill, three anonymous reviewers, and especially Scott Leibowitz for providing valuable comments and edits on manuscript drafts. We especially thank Jeff Back and Conrad Field for their field efforts, and Phil North for his support and encouragement.


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Copyright information

© Society of Wetland Scientists 2012

Authors and Affiliations

  • Coowe M. Walker
    • 1
    Email author
  • Ryan S. King
    • 2
  • Dennis F. Whigham
    • 3
  • Steven J. Baird
    • 1
  1. 1.Kachemak Bay National Estuarine Research ReserveHomerUSA
  2. 2.Department of Biology, Center for Reservoir and Aquatic Systems ResearchBaylor UniversityWacoUSA
  3. 3.Smithsonian Environmental Research CenterEdgewaterUSA

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