Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Steven F. Railsback; Bret C. HarveyJason L. White
    Date: 2015
    Source: Transactions of the American Fisheries Society. 144(6): 1220-1236
    Publication Series: Scientific Journal (JRNL)
    Station: Pacific Southwest Research Station
    PDF: Download Publication  (910.0 KB)


    We address the question of spatial extent: how model results depend on the amount and type of space represented. For models of how stream habitat affects fish populations, how do the amount and characteristics of habitat represented in the model affect its results and how well do those results represent the whole stream? Our analysis used inSalmo, an individual-based model of anadromous salmonid spawning, incubation, and juvenile rearing. The model was applied to 12 sites, totaling 4.0 km in length, on Clear Creek, California, treating the simulated 4.0 km as a synthetic whole stream. Simulation experiments examined responses of anadromous salmonid spawning and rearing success to habitat variables, such as flow and temperature, when the model included each individual site, all sites, and random combinations of two to nine sites. Some responses, such as temperature effects on egg incubation, were insensitive to spatial extent. Other responses, including the effects of flow on the production of large juveniles, varied sharply among sites and varied with spatial extent. Most small sites had little effect on overall results, but one small site provided exceptionally good juvenile rearing habitat and strongly affected the responses of the entire stream. Larger sites (length > 15 channel widths) in distinct habitat types (e.g., highly disturbed and recently restored) also had strong effects. Including more or longer sites generally increased model representativeness but not consistently. Results highly representative of the entire stream could also be obtained by combining large sites in typical habitat with “hot spots” of especially productive habitat. Finally, sites lower in the watershed appear to be more important to model results and anadromous salmonid spawning success because more juveniles migrate through them.

    Publication Notes

    • You may send email to to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • 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.


    Railsback, Steven F.; Harvey, Bret C.; White, Jason L. 2015. Effects of spatial extent on modeled relations between habitat and anadromous salmonid spawning success. Transactions of the American Fisheries Society. 144(6): 1220-1236.


    Google Scholar


    salmonids, modeling, instream flow, fish-habitat relationships

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page