LOCATION DUGUALLA WAEstablished Series
TAXONOMIC CLASS: Euic, mesic Halic Haplosaprists
TYPICAL PEDON: Dugualla muck, pasture, in a relict lagoon depression protected by a tide gate at sea level. When described on October 5, 2005 the soil was saturated below 86 cm. (Colors are for moist soil unless otherwise noted.)
0a1--0 to 28 cm; black (10YR 2/1) muck, very dark gray (10YR 3/1) dry; massive; slightly hard, very friable, non-sticky and non-plastic; 20 percent fiber, 5 percent rubbed; few fine roots; many very fine tubular pores; common prominent very pale brown (10YR 7/4), very pale brown (10YR 8/2) dry iron depletions throughout; slightly acid (pH 6.5); strongly saline (EC > 40 dS/m); clear wavy boundary. (10 to 30 cm thick)
0a2--28 to 51 cm; very dark brown (7.5YR 2.5/2) muck, brown (7.5YR 4/2) dry; strong very thin platy structure; hard, very friable, non-sticky and non-plastic; 10 percent fiber, 3 percent rubbed; few very fine roots; few very fine tubular pores; common distinct dark yellowish brown (10YR 4/6), yellowish brown (10YR 5/6) dry iron-manganese concentrations along root channels, common distinct very pale brown (10YR 7/4), very pale brown (10YR 8/2) dry iron depletions throughout; slightly acid (pH 6.3); strongly saline (EC > 40 dS/m); gradual wavy boundary.
0a3--51 to 66 cm; very dark brown (10YR 2/2) muck, very dark gray (10YR 3/1) dry; moderate medium platy structure; moderately hard, very friable, non-sticky and non-plastic; 20 percent fiber, 5 percent rubbed; few fine roots; many very fine irregular pores; 20 percent marine shell fragments; neutral (pH 7.1); strongly saline (EC > 40 dS/m); gradual wavy boundary.
0a4--66 to 152 cm; very dark brown (7.5YR 2.5/2) muck, brown (7.5YR 4/2) dry; massive; hard, very friable, non-sticky and non-plastic; 5 percent fiber, 0 percent rubbed; few very fine roots; few very fine irregular pores; neutral (pH 7.2); strongly saline (EC > 40 dS/m).
TYPE LOCATION: South end of Lopez Island, San Juan County, Washington; 460 meters east and 560 meters north of southwest corner Section 11, T. 34 N., R. 2 W. Willamette Baseline Meridian; USGS Richardson NE quarter quadrangle; Latitude 48 degrees 27 minutes and 15 seconds North, Longitude 122 degrees 54 minutes and 13 seconds West.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 10 to 11 degrees C.
Depth to mineral soil material - greater than 130 cm
Reaction - slightly acid to neutral
Electrical conductivity - greater than 30 dS/m for 6 months or more throughout the upper 130 cm
Rubbed fiber content - averages less than 16 percent throughout the upper 130 cm
Oa1 horizon
Value - 2 or 3 moist, 3 or 4 dry
Chroma- 1 or 2 moist and dry
Oa2,3,4 horizons
Hue - 7.5YR to 10YR
Value - 2 to 3 moist, 2 to 4 dry
Chroma - 1 to 3 moist or dry
COMPETING SERIES: There are no competing series in this family.
GEOGRAPHIC SETTING: Dugualla soils are in natural and protected (relict) lagoons and depressions of marine shore complexes with slopes of 0 to 2 percent at elevations of 0 to 2 meters. They formed in salt water influenced herbaceous organic deposits. The climate is characterized by warm dry summers and mild moist winters. Annual precipitation ranges from 455 to 1,015 millimeters. Average annual temperature ranges from 9 to 11 degrees C. The frost-free period is about 200 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Coveland, Coupeville, and Shalcar soils. Coveland and Coupeville soils are mineral soils. Shalcar soils have a loamy substratum at depths of less than 100 cm.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Very poorly drained. Saturated hydraulic conductivity is moderately high. Dugualla soils that are drained or protected by tide gates can have a water table at or above the soil surface from November through May. Unprotected or un-drained Dugualla soils will have a water table fluctuating with tide levels at or above the soil surface throughout the year. In areas that are drained or protected by tide gates, the water table can drop to below 60 cm from June through October.
USE AND VEGETATION: Dugualla soils are used mainly for watershed and wildlife habitat. Potential natural vegetation consists of sedges, cattails, reeds and Virginia glasswort.
DISTRIBUTION AND EXTENT: Puget Sound, Northwest Washington; MLRA A2, Northern Part. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: San Juan County, Washington - 2006. Name is taken from Dugualla Bay on Whidbey Island in Island County.
REMARKS:Diagnostic horizons and features recognized in this pedon include:
Organic soil material with less than 16 percent rubbed fiber - the zone from the surface to 152 cm (Oa horizons)
Electrical conductivity of greater than 40 dS/m throughout
Control section - the zone from 0 to 130 cm