You are here

Biophysical ecology of streams in high elevation wet meadows

April, 2015

Mapping salmon nesting sites in high elevation stream in wet meadow
Mapping salmon nesting sites in high elevation stream in wet meadow
Many of the most critical riverine aquatic ecosystems under Forest Service management occur in high elevation wet meadows. These streams and riparian areas are often host to threatened and/or endangered species. The wet meadow ecosystems are at high risk from climate changes, wildfires, and water diversions.

A typical wet meadow in the upper Middle Fork Salmon River, Idaho is the site of several prior and current investigations of stream ecosystem dynamics. Research topics include:

  • Geologic controls on distribution of salmon spawning sites.
  • Potential for mid-winter streambed scour and destruction of fish egg nest sites in climates with more winter rain and earlier snowmelt.
  • Controls on transport, deposition and ecologic effects of fine sand in gravel-bed streams.
  • The role of habitat connectivity in fish population dynamics.
  • The importance of hyporheic flow in selection of salmon spawning sites.

This research had contributed to better understanding of these critical high elevation ecosystems by developing and using objective, repeatable, and process-based techniques of analysis.

Key Findings

  • The glacial history of high elevation areas has strong effects on the location of the best fish habitat.
  • Low stream gradients and large sediment sizes buffer the effects of streambed scour and destruction of fish egg nest sites from increased mid-winter flows.
  • Chronic supplies of fine sediment are slightly more detrimental to fish habitat than pulsed inputs from debris flows.
  • At the reach scale, the quality and size of good habitat patches are more important for fish population dynamics than habitat connectivity.
  • Local surface water depth and velocity are more important in selection of salmon spawning sites than the intensity of hyporheic flow (i.e., percolating flow of water through the sand, gravel, sediments and other permeable soils under and beside the open streambed).


New techniques have been developed to map stream bathymetry and model flow conditions throughout meadow systems. A free GIS software toolkit, the River Bathymetry Toolkit, has been developed to automatically map and graph many of the important stream attributes using high resolution stream bathymetry. These tools allow managers to consider stream ecosystem function at scales ranging from meters to tens-of-kilometers.

River bathymetry map
River bathymetry map


McKean, James (Jim) A. ; Tonina, D. ; Bohn, C. ; Wright, C. W. , 2014
Maturana, Oscar ; Tonina, Daniele ; McKean, James (Jim) A. ; Buffington, John M. ; Luce, Charles H. ; Caamano, Diego , 2013
Tonina, D. ; McKean, James (Jim) A. ; Tang, C. ; Goodwin, P. , 2011
McKean, James (Jim) A. ; Isaak, Daniel J. ; Wright, Wayne , 2009

Project Contact: 

Daniele Tonina - University of Idaho