The geographic distribution of stream reaches with potential to support high
quality habitat for salmonids has bearing on the actual status of habitats and populations over
broad spatial extents. As part of the Coastal Landscape Analysis and Modeling Study (CLAMS),
we examined how salmon-habitat potential was distributed relative to current and future (+100
years) landscape characteristics in the Coastal Province of Oregon, USA. The intrinsic potential
to provide high-quality rearing habitat was modeled for juvenile coho salmon (Oncorhynchus
kisutch) and juvenile steelhead (O. mykiss) based on stream flow, valley constraint, and stream
gradient.
See Supplemental Information for additional detail.
BLM: (Bureau of Land Management)
WOPR: (Western Oregon Plan Revision)
WOPR Theme Group: FSH (Fish)
PRMP: (Proposed Resource Management Plan)
This data is a PRMP release version of the data fsh_aa_a_HighIntPot_steelhead_arc.
Land ownership, use, and cover were summarized for 100-m analysis buffers on either
side of stream reaches with high intrinsic potential and in the overall area encompassing the
buffers. Past management seems to have concentrated nonindustrial private ownership,
agriculture, and developed uses adjacent to reaches with high-intrinsic potential for coho salmon.
Thus, of the area in coho salmon buffers, 45% is either non-forested or recently logged but only
10% is in larger-diameter forests. For the area in steelhead buffers, 21% is either non-forested or
recently logged while 20% is in larger-diameter forests. Older forests are most extensive on
federal lands but are rare on private lands, highlighting the critical role for public lands in near17
term salmon conservation. Agriculture and development are projected to remain focused near
high-intrinsic-potential reaches for coho salmon, increasing the importance of effectively
addressing nonpoint source pollution from these uses. Percentages of larger-diameter forests are
expected to increase throughout the province, but the increase will be only half as much in coho
salmon buffers as in steelhead buffers. Most of the increase is projected for public lands, where
policies emphasize biodiversity protection. Results suggest that widespread recovery of coho
salmon is unlikely unless habitat can be improved in high-intrinsic-potential reaches on private
lands. Knowing where high-intrinsic-potential stream reaches occur relative to landscape
characteristics can help in evaluating the current and future condition of freshwater habitat,
explaining differences between species in population status and risk, and assessing the need for
and feasibility of restoration.
