According to the 1936 State of Oregon Forest Type Map,54 which predates extensive logging activities, about 70% of the Lake County portion of Klamath Province was covered by trees, primarily ponderosa pine. A small area above about 7,000 feet elevation southeast of Lakeview was forested with such species as true fir. About 30% of this portion of the province was unforested. Of that, about 5% was cultivated, 5% was lakebed in the vicinity of Lakeview, and the remaining 20% was likely shrub–grassland. Only about 1% of the Lake County portion of the province was covered by stands of juniper. These stands were mainly in two locations, about 12 miles west of Lakeview and south of Highway 66, and on the rocky plateaus sloping east between Warner Mountains and Warner Valley.
In the portion of Klamath Province in Klamath and Jackson counties, about 50% was covered by trees consisting primarily of ponderosa pine. In addition, about 10% of the area was covered by stands of juniper distributed throughout the area. Unforested areas, which were probably cropland and shrub–grass rangelands, covered about 40% of the area; and lakes, marshes, and wet meadows occupied about 10% of the area.
Radical changes since 1936 in Klamath Province of Oregon include expanded juniper coverage and increased cropland acreage resulting from sprinkler irrigation and the drainage of marshes and shallow lakes.
Natural grasslands in Klamath Province of Oregon occur only on bottomlands, and the vegetation varies according to degree and duration of wetness. The driest natural grasslands in Klamath Province are well-drained bottoms on which basin wildrye dominates a wide variety of grass species. Associated soils include the Modoc series. The wettest natural grasslands in the province are wet mountain meadows on which tufted hairgrass dominates in a wide variety of grasses, sedges, and rushes. Associated soils include Gooselake, Klamath, and Lakeview series. Meadows of intermediate wetness are dominated by a variety of bluegrasses, including Leiberg, Nevada, Kentucky, Canby, and Sandberg, and a wide variety of other grasses, sedges, and rushes. Associated soils include Whitworth and Yocum series.
Marshlands, the transitions from lake to meadow, are typified by bullrushes and cattails. Associated soils include Tulano, Algoma, Yamsay, and Moyina series.
Natural shrub–grasslands occur within the lake basins of Klamath Province in Oregon mainly on lakebed terraces and stony sloping tuffaceous plateaus and on some south-facing slopes at lower elevations in mountainous areas (Fig. 29).
Figure 29: Rangeland on ancient-lake terraces in the easter portion of Klamath Province, Oregon
Shrub–grasslands on very shallow or claypan soils are strongly dominated by low sagebrush with minor amounts of shrubby buckwheat and bitterbrush. Associated soils include Lorella and Booth series.
Klamath Province shrub–grasslands on moderately deep soils are notable for their wide array of shrub species. Big sagebrush and bitterbrush are widely prominent. Other shrubs include Klamath plum, serviceberry, desert gooseberry, shrubby buckwheat, gray horsebrush, gray and green rabbitbrushes, curlleaf mountain-mahogany, chokecherry, wax currant, granitegilia, rose, mountain snowberry, blue elderberry, oceanspray, and, on steep north exposures, birchleaf mountain-mahogany.
The Klamath Province shrub–grasslands also are notable for the wide variety of perennial grass and forb species in plant communities. It is not uncommon for a sizable plant community in relatively good ecological status to contain about 10 perennial grass species and about 20 perennial forb species. Soils associated with shrub–grasslands in the province in Oregon include Calimus, Bluejoint, Drews, Hartig, Lorella, Crume, Modoc, and Nuss series.
Most shrub, grass, and forb species in this province in Oregon are the same species found to the east and north in other Oregon ecological provinces. However, at least three species common in Klamath Province in Oregon do not grow in other eastern Oregon provinces: woolly wyethia, Klamath plum, and birchleaf mountain-mahogany. In its wide variety of shrub, grass, and forb species, Klamath Province represents a transition between other eastern Oregon provinces and Siskiyou Province in southwest Oregon, which also is typified by a wide variety of native species many of which apparently do not occur in eastern Oregon.
Natural juniper sites are considered to be those on which mature juniper trees constitute 5% or more of canopy cover and in which all age classes of juniper appear, indicating the stand’s perpetuation. East of Warner Mountains in Lake County, natural juniper stands occur on extensive areas of basalt rubbleland—land where rock outcrops and stone-size rubble cover about 90% of the land surface. Plant growth is confined to areas between the rubble; low sagebrush is the dominant shrub (Fig. 30). These areas are likely the same areas that were mapped as juniper trees in 1936. Similar examples of natural juniper stands also occur to the west in the province. Associated soils include the Hart–Rockland and the Lorella–Booth–Rockland complexes.
Figure 30: Managed natural shrub-grassland on very stony land producing Idaho fescue, low sagebrush, and scattered western juniper in the eastern portion of Klamath Province, Oregon
Other natural juniper stands are on undulating south-facing slopes having shallow, stony soils. Bitterbrush, big sagebrush, and a variety of bunchgrasses grow in the understory. Associated soils include Lorella and Fuego series.
In addition to juniper, stands of other coniferous trees in 1936 covered about 70% of Klamath Province. In this area, ponderosa pine is the most widespread tree species and grows in a variety of environments because of its wide ecological amplitude. In Klamath Province, it appears that ponderosa pine can encroach into disturbed forests, including into stands of white fir.39
White fir is the next most widespread tree species in the province. (Both white fir and grand fir are collectively called white fir in this instance.) Commonly, a single tree will have needle characteristics of both species, indicating that cross-breeding has produced a hybrid. This also occurs in Blue Mountain Province of Oregon where the two species intermingle. Fred Hall, an ecologist in Region 6 of the U.S. Forest Service (Portland), once aptly suggested the hybrid should be classified as Abies grandcolor to dispense with debate (personal communication to author). The ecological amplitude of white fir in Klamath Province in Oregon extends from the dry ponderosa pine zone, where it is normally on north exposures, to high cold ridges of about 6,700 feet elevation.
Douglas-fir is common only in the western portion of Klamath Province. Sugar pine extends throughout the province but is not dominant in any stand. It usually is on north-facing slopes in the province east of Klamath Falls and on south-facing slopes west of Klamath Falls. It appears to be somewhat tolerant of shade and always grows in mixed stands. Incense cedar generally is associated with sugar pine in Klamath Province in Oregon.
Lodgepole pine is uncommon in Klamath Province but grows in cold areas above about 6,700 feet elevation, such as on Swan Lake Point and Yainax Butte. It also occurs in concave cold and wet locations.
Soils associated with pine, fir, and mixed pine-fir forests include Mound, Woodcock, Tournquist, Lobert, and Bly series.
Aspen is the most abundant and widespread native deciduous tree in the province and is restricted to cold, wet areas. Soils associated with aspen stands include Mitten Springs series.
The greatest abundance of tree species, and for that matter of all plant species, is in the far western, most moist portion of Klamath Province in Oregon. This area is close to the Siskiyou and Cascade provinces.