Fig 1.
Diagram of model linkages between restoration actions, habitat conditions, life-cycle model input parameters, and salmon population response.
Fig 2.
The HARP model has three modules (blue circles) that translate geospatial data into habitat data layers, diagnostic habitat scenarios, and life-cycle model outputs (yellow squares).
Fig 3.
Map of the Chehalis River basin showing major water bodies, tributaries, cities, towns, highways, and mountain ranges.
Table 1.
Reference condition methods.
Fig 4.
Distribution of large rivers (bankfull width >20 m) and small streams (<20 m bankfull width) in the Chehalis River basin (left panel). Map of the 63 subbasins (black boundaries) and Ecological Regions (colored regions) (right panel). Gray-striped subbasins are not included in Ecological Regions.
Table 2.
Habitat typing system.
Fig 5.
Area of floodplain habitat lost and gained (current floodplain area–natural potential floodplain area). Increases in lakes and ponds are due to constructed reservoirs, retention ponds, and other small impoundments.
Table 3.
Summary of habitat changes in the Chehalis River basin and Grays Harbor tributaries.
Table 4.
Changes in channel length.
Fig 6.
Change in stream shade (canopy opening angle).
Frequency distributions (proportion of total reaches) of natural potential and current canopy opening angles in the Chehalis River basin. Note the large increase in very wide canopy opening angles (>100°) and large decrease in narrow angles (<10°).
Fig 7.
Spatial distribution of restoration potentials.
Maps of restoration potential for six habitat attributes under current climate conditions and development, indicating spatial variation in restoration potential without effects of climate change or future development. Beaver is the mean beaver intrinsic potential score by Geospatial Unit (GSU). Barriers is the potential increase in mean passability percentage by GSU if migration barriers are removed. Fine sediment is the potential decrease in fine sediment if forest road surface erosion is reduced (mean historical percent fines–mean current percent fines). Wood is the potential increase in hectares of spawning gravel by GSU via increasing wood abundance (historical spawning gravel area–current spawning gravel area, in hectares). Shade shows the stream temperature restoration potential (Δ°C) by GSU via riparian shade restoration (mean historical °C–mean current °C). Floodplain indicates the potential increase in hectares of floodplain habitat area by GSU via restoration of floodplain connectivity (historical ha–current ha of floodplain habitat).