On public lands, restoration activities addressing the effects of land-use activities on aquatic habitats rely increasingly on ecosystem principles across large spatial scales. In western Oregon, however, public lands often occur in a matrix of private timberlands where harvest activities are subject to other regulations. These industrial forest systems have rarely been considered in the integrated management of forested landscapes. Our goal is to expand the understanding of physical and biological processes in streams subjected to contemporary forest harvest in western Oregon. This study will initiate a long-term program examining fish and riparian invertebrates associated with temporally varying harvest activities.
Critical questions concerning contemporary timber harvest
practices
remain unanswered. Fundamental to answering these
questions is determining how harvest activities in headwaters
affect fish assemblages and behavior across the stream
network. We anticipate that changes in habitat, water quality,
or
food supply will affect fish in a dynamic way, and we propose
to address the following questions:
- How do changes in physical and biological characteristics of tributaries without fish
seasonally influence habitat quality in other portions of the stream network?
- How do seasonal hydrologic changes
in headwater streams affect fish abundance and distribution?
- Does the abundance or diversity of fish fauna decline
in response to changed habitat
quality, or do organisms seasonally move to areas where
habitat quality remains high?
Because interpretation of results
can
be highly context-dependent, it is important to collect
data across a variety of temporal and spatial scales. Here
we
use passive integrated transponder (PIT) tags with both
mobile and fixed site antennas, in conjunction with electrofishing,
to characterize fish distribution and abundance at time
scales
of continuous, seasonal, and yearly at spatial scales from
individual habitat units to multiple watersheds.
For additional information about this research study see
the CFER
Annual Report. (3.6 MB)
