The Woodland Fen ecological site is similar to the Sphagnum Fen site. Areas of the Woodland Fen site occur near high-volume springs, commonly are small in size, and are surrounded by Douglas fir, mountain hemlock, western hemlock, and Shasta red fir sites. This site is subject to active and continuous water movement on and below the surface. It is in the Boundary Springs area, the Thousand Springs area, and other spring-fed areas.
Because of the small size of the areas and the adjacent mature forests, this site is comprised of more shade-tolerant plants and has a continuous carpet of sphagnum moss. The dominant plants include panicled bulrush (Scirpus microcarpus), water sedge (Carex aquatilis), bog blueberry (Vaccinium uliginosum), and gray alder (Alnus incana). Areas of this site are very diverse and support an abundance of forbs and few grasses. Because this site grades from fen to forest, in some areas it is difficult to differentiate this true site type from adjacent areas that are transitional to forest sites. Many forbs of the adjacent forest sites are in the transitional zone.
Soils on this site consist of mucky peat about 25 to 30 inches thick over mineral soil material. Although the soils on this site are similar to those of the Sphagnum Fen sites, the organic layer of these soils is not as thick and the soils generally are better drained.
The accumulation of organic matter and substrate from windthrown timber on this site is similar to that of the Sphagnum Fen site. In many areas, fallen timber serves to incubate the shrubby phase of the site. In areas where the organic matter is about 35 inches thick over mineral soil material or gravel, a plant community of booth willow (Salix boothii), bog blueberry (Vaccinium uliginosum), and water sedge (Carex aquatilis) can become established. Occasional fires can consume the extra organic matter and return the plant community to dominantly wet bulrush (Dorr and others, 2000).
The Ashy Glacial Meadow ecological site occurs at lower elevations on the western edge of the park, in the Poison Meadow area. This site occurs at the contact between the volcanic, ashy soils and the older glaciated sediment. The site generally is moist, is in shallow depressions and along intermittent streams, and is influenced by adjacent moving freshwater and a local high water table.
The dominant plant community on this site consists of widefruit sedge (Carex angustata), tufted hairgrass (Deschampsia caespitosa), pullup muhly (Muhlenbergia filiformis), and bog blueberry (Vaccinium uliginosum). The presence of widefruit sedge rather than the more ubiquitous water sedge may be attributable to the lower anaerobic condition of the site. Water sedge has the ability to absorb amino acids from the surrounding organic soils, which may make it more competitive in these cold, wet areas (Raab, 1999). Widefruit sedge also is common in moist areas at lower elevations in the Rogue River and Winema National Forests.
The Ashy Glacial Meadow site is associated with the Ashy Glacial Prairie site and is surrounded by western hemlock and Shasta red fir forest sites and an occasional incense cedar site. The Ashy Glacial Meadow site has a rich forb component, and it provides significant amounts of forage for ungulates in summer. It can produce 4,800 to 6,300 pounds of air-dry vegetation per acre per year. The proximity of hiding and thermal cover make this site attractive to elk and mule deer.
The Ashy Glacial Prairie ecological site is in the Poison Meadow area. This site is adjacent to the Ashy Glacial Meadow site and is transitional into the forest sites. Soils in the Ashy Glacial Prairie site are similar to those in the western hemlock forest sites, but they are more moist, have a thicker solum, and are more than 40 inches deep to a duripan.
