Citation | Tripp, D. 1998. Evolution of fish habitat structure and diversity at log jams in logged and unlogged streams subject to mass wasting. In: Hogan, D.L., P.J. Tschaplinski, and S. Chatwin (Editors). B.C. Min. For., Res. Br., Victoria, B.C. Land Manage. Handb. No. 41. |
---|---|
Organization | FLNRO |
URL | https://www.for.gov.bc.ca/hfd/pubs/docs/Lmh/Lmh41.htm |
Abstract/Description or Keywords | Large woody or organic debris is an essential component of most streams on the Queen Charlotte Islands (Hogan 1986; Tripp and Poulin 1986). It is frequently also closely linked with upslope processes, inasmuch as debris torrents and other mass wasting events appear to be a significant source of debris for streams on the Queen Charlotte Islands (Schwab, this volume). Where the gradient is steep enough, slides or torrents may be carried down in small streams for a considerable distance before halting in a lower gradient reach. When the floodplain is confined between steep hillsides, debris torrents also enter the low gradient sections of larger streams directly from gully failures alongside the stream. Most of the large organic debris in medium-size streams (15–25 m wide ) on the Queen Charlotte Islands is organized into log jams (Hogan 1989). These log jams physically occupy a significant portion of the total stream length available to fish. Because log jams also control many of the habitat characteristics upstream of a jam as well as below a jam, understanding how the fish habitat at log jams develops or evolves in many streams can require study of most of the fish habitat present. Logging to the stream edge changes the type and rate of debris entering a stream. In steep land areas on the Queen Charlotte Islands, logging in upslope areas also accelerates the amount of sediment and debris introduced into streams (Rood 1984). Both factors should affect the structure of the log jams, but to what degree or how quickly is unknown. The present study attempts to determine how log jams and the fish habitat associated with them evolve over time. It also attempts to determine if log jams in logged streams show the same patterns and rates of change as log jams in unlogged streams. |
Information Type | Article |
Regional Watershed | Coast Region |
Sub-watershed if known | |
Aquifer # | |
Comments | |
Project status | complete |
Contact Name | |
Contact Email |