Following a river wherever it goes: beneath the surface of mountain streams.Author(s): Jonathan Thompson; Sally Duncan
Source: Science Findings 67. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 5 p
Publication Series: Science Findings
Station: Pacific Northwest Research Station
PDF: Download Publication (669.0 KB)
DescriptionThe flow of a mountain stream is difficult to follow, especially when it weaves in and out of the channel, flowing through streambanks and seeping through the streambed. Flowing belowground, the stream water mixes with ground water in the riparian aquifer before reemerging in the channel, sometime later and somewhere further downstream. Underground, the water undergoes filtration, nutrient cycling, and temperature moderation. In addition, the belowground environment, called the hyporheic zone, provides habitat for a diversity of aquatic organisms.
The hidden nature of the hyporheic zone has made it a difficult subject to study. Only recently have researchers begun to understand the aboveground influences on belowground flows. PNW Research Station studies in the western Cascades have shown how stream size and channel morphologic features affect the amount, distance, and duration of hyporheic flows.
As the ecological importance of the hyporheic zone becomes more widely recognized, there is increasing focus on the influence of management decisions on the hyporheic zone. Using lessons learned from the 1996 floods that impacted the H.J. Andrews Experimental Forest in western Oregon, scientists are gauging the effects of disturbance on the belowground portions of stream ecosystems. By extrapolating from flood disturbances to human influence, land managers will be better able to understand how management activities that simplify stream channels limit the exchange of stream water with the hyporheic zone and thereby alter stream nutrient cycles, temperature regimes, and the habitat available for hyporheic-dwelling organisms.
- Visit PNW's Publication Request Page to request a hard copy of this publication.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationThompson, Jonathan; Duncan, Sally. 2004. Following a river wherever it goes: beneath the surface of mountain streams. Science Findings 67. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 5 p
KeywordsScience Findings 67
- Thermal pollution in rivers: Will adding gravel help to cool them down?
- Flood disturbance in a forested mountain landscape: interactions of land use and floods.
- Isotope hydrology and baseflow geochemistry in natural and human-altered watersheds in the Inland Pacific Northwest, USA
XML: View XML