LOCATION WATERFALL               AK

Established Series
Rev. RCH/DJL/JPM
02/2022

WATERFALL SERIES

The Waterfall series consists of shallow to bedrock, well or moderately well drained soils that formed in colluvium. Waterfall soils are on backslopes and footslopes of hills and mountains. Slopes range from 35 to 100 percent. Mean annual precipitation is about 120 inches, and mean annual temperature is about 45 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, acid Lithic Cryorthents

TYPICAL PEDON: Waterfall extremely gravelly loam -- on a 90 percent N-facing slope under forest vegetation at an elevation of 900 feet. (All colors are for moist soil)

Oi--2 inches to 0; undecomposed forest litter; 20 percent gravel; clear smooth boundary. (2 to 8 inches thick)

C--0 to 17 inches; strong brown (7.5YR 5/6) extremely gravelly loam; weak fine subangular blocky structure; friable, slightly sticky and slightly plastic; common coarse, medium, fine and very fine roots; 65 percent gravel; very strongly acid (pH 4.5); abrupt wavy boundary.

R--17 inches; sandstone

TYPE LOCATION: Ketchikan Area, Alaska; on Suemez Island, 500 feet south and 500 feet west of the NE corner of section 28, T.76S., R.80E., Copper River Meridian.

RANGE IN CHARACTERISTICS: Depth to bedrock ranges from 14 to 20 inches. Mean annual soil temperature is about 42 degrees F. Mean summer soil temperature is about 46 degrees F. Reaction is extremely acid to very strongly acid throughout the profile.

The O horizon has rock fragment content ranging from 0 to 20 percent.

The C horizon has hue from 5YR to 10YR, value from 3 to 5 moist, and chroma from 2 to 6 moist. Texture is loam or silt loam. Coarse fragment content ranges from 40 to 75 percent gravel and 10 to 15 percent cobble.

COMPETING SERIES: These are the Merino and Pendergrass series in an adjacent family. Merino and Pendergrass soils have pH of 5.5 (H2O,1:1) or greater in the control section.

GEOGRAPHIC SETTING: Waterfall soils are on backslopes and footslopes of hills and mountains. These soils formed in colluvium and are underlain by quartz sandstone, graywacke, diorite, or granite.

The climate is humid maritime with mean annual precipitation of 100 to 200 inches. The mean annual temperature is 45 degrees F. Slopes range fro;m 35 to 100 percent. Elevation ranges from 100 to 1000 feet.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Kina, Maybeso, McGilvery, Tolstoi, Tonowek, Tuxekan, and Wadleigh soils. Kina and Maybeso are organic soils in valleys and on hillsides. McGilvery is a well drained organic soil overlying bedrock on mountainsides. Tolstoi and Wadleigh have spodic horizons and are on mountainsides. Tonowek and Tuxekan are alluvial soils on floodplains and alluvial fans.

DRAINAGE AND PERMEABILITY: Well or moderately well drained. Moderately rapid permeability. Medium to rapid runoff.

USE AND VEGETATION: The Waterfall soils are used for timber production, watershed protection, wildlife habitat, and recreation. The overstory vegetation is dominantly western hemlock and Sitka spruce, with lesser amounts of western red cedar and Alaska yellow cedar. The understory vegetation includes blueberry and huckleberry, ferns and mosses.

DISTRIBUTION AND EXTENT: Southeast Alaska. The series is of minor extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA

SERIES ESTABLISHED: Ketchikan Area, Alaska. 1994.

REMARKS: Diagnostic horizons and features recognized in this soil are: the lack of a diagnostic subsoil horizon; cryic temperature regime; lithic contact at 17 inches; loamy-skeletal particle size from 10 inches to bedrock; a pH of less than 5.0 in the control section.

---

National Cooperative Soil Survey
U.S.A.