This site is significantly drier than the Ashy Glacial Meadow site, and it supports dominantly grasses rather than sedges. The dominant plants include western needlegrass (Achnatherum occidentale ssp. californicum), blue wildrye (Elymus glaucus ssp. glaucus), pullup muhly (Muhlenbergia filiformis), and western coneflower (Rudbeckia occidentalis). The large bunchgrass and taller western coneflower distinguish this site. Tree species regularly invade the site (within the confines of the duripan at a depth of 40 inches), and it has probably remained as a rangeland site as a result of occasional fire. A slightly higher frequency of fire can be expected on this site than on adjacent forest sites.
The “poison” in the meadow commonly is tall larkspur (Delphinium occidentale), which is very toxic to cattle early in the season. Another toxic plant on this site is false hellebore (Veratrum californicum), which can poison livestock if the young shoots are eaten. There is considerable evidence of a long history of livestock grazing on this site before the area became part of Crater Lake National Park. In some areas the forbs are very abundant, and the historic climax plant community probably had less western coneflower and more western needlegrass.
Two forested areas are in this plant association. One is the forested riparian zone along Annie Creek (see fig. 3, page 99). The ecological site in this zone is Engelmann spruce/gray alder/sedge (Picea engelmannii/Alnus incana/Carex). Engelmann spruce is considered to be the historic climax tree species in the plant community. Natural fire occurs infrequently in this riparian area. Fire-sensitive Engelmann spruce trees that are as much as 300 years old have been found on this site, indicating long periods without fire (Kovalchik, 1987). The fires that do occur generally consume all of the vegetation and the successional process is restarted.
There are four plant community successional stages on this site. The first plant community to become established after a fire typically is a brush/ forb/grass-sedge community. The second commonly consists of lodgepole pine, which is a pioneer species and thus becomes established easily. When the lodgepole pine stand approaches maturity, white fir is already established in the understory and growing into the overstory. Over time, the lodgepole pine dies and white fir becomes the major tree species. Given more time and no major disturbances, Engelmann spruce becomes established and is dominant in the stand.
The second forested area in this plant association is associated with the Thousand Springs area. In this area, the climatic environment is influenced by the continual overland flow of water. The year-round climate is moderate with few annual fluctuations. This favorable climate allows for growth of more diverse vegetation. Tree species present in the overstory and understory include Douglas fir, Engelmann spruce (Picea engelmannii), Shasta red fir, western hemlock (Tsuga heterophylla), white fir, and mountain hemlock. The understory composition is extremely diverse. The major plants are queenscup beadlily (Clintonia uniflora), prince’s pine (Chimaphila umbellata), northern twinflower (Linnaea borealis), western teaberry (Gaultheria ovatifolia), blue huckleberry (Vaccinium membranaceum), sidebells pyrola (Orthilia secunda), and coolwort foamflower (Tiarella trifoliata var. trifoliata). Ground fires in this area appear to have occurred very infrequently. Wetness and the abundant green vegetation make it difficult for ground fires to move through this area. The fires that did occur probably were stand-replacing crown fires that produced enough heat to preheat the taller vegetation, allowing the fires to burn through and consume all the material down to the saturated zone. These infrequent, widespread, stand-replacing fires occurred at intervals of perhaps 400 to 500 years (Hemstrom and Franklin 1982; Lotan and others, 1981).
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