Soils of the Beaver Creek Watershed

Principal soil series found along the lower elevation streams, and in the pinyon-juniper and ponderosa pine types on the Beaver Creek Experimental Watershed (BCEW) are the Anthony, Brolliar, Siesta, Sponseller, and Springerville series (Table 1).

Table 1. Soil series classified according to the current system of classification.

Anthony Series

The Anthony series consists of deep, well-drained soils on nearly level and smooth bottom lands and on first and second terraces above stream channels. These soils formed in mixed material washed mostly from sandstone but partly from limestone, basalt, schist, rhyolite, and granite. They occur along Oak Creek and the Verde River, at elevations of 945 to 1,067 m (3,100 to 3,500 ft), where the annual precipitation is about 300 mm (12 inches). These soils are associated with Gila and Toquop soils. The vegetation consists of creosotebush, mesquite, cacti, and galleta. Most of the acreage has been leveled and is used for cultivated crops under irrigation.

Anthony soils are calcareous to the surface. Typically, they have a reddish-brown surface layer that is slightly hard when dry and is massive. There is no clearly expressed subsoil. The substratum is fine sandy loam, stratified in places with fine sand or loamy fine sand. Like the surface layer, it is reddish brown, massive, and slightly hard when dry. The reddish-brown color is typical of these soils.

Brolliar Series

The Brolliar series consists of moderately deep and deep, well-drained, noncalcareous soils on nearly level to hilly uplands. These soils formed in material weathered from porous basalt. They occur at elevations of 1,982 to 2,318 m (6,500 to 7,600 ft), where the annual precipitation is 500 to 580 mm (20 to 23 inches). These soils adjoin Siesta, Sponseller, and Friana soils. Plant cover consists chiefly of ponderosa pine, Gambel oak, Arizona fescue, mountain muhly, bluegrass, squirreltail, and junegrass.

Brolliar soils have a dark-brown surface layer that is soft when dry and has a platy structure. Their subsoil is reddish brown and is hard when dry. It has blocky structure. Basalt bedrock is at a depth of 0.6 to 1.5 m (2 to 5 ft). Stones and cobblestones cover 20 to 60 % of the surface of most areas. A layer of undecomposed and partly decomposed pine needles overlies the mineral soil.

Siesta Series

The Siesta series consists of moderately deep and deep, well-drained, noncalcareous soils on gently rolling and undulating uplands. These soils occur in the eastern part of the watershed, at elevations of 2,074 to 2,440 m (6,800 to 8,000 ft), where the average annual precipitation is 500 to 560 mm (20 to 22 inches). They adjoin Brolliar, Sponseller, Springerville, Friana, and Gem soils. Plant cover consists of a good stand of ponderosa pine, some Gambel oak, Arizona fescue, junegrass, mountain muhly, blue grama, iris, lupine, and annual weeds.

Siesta soils have a reddish-brown surface layer that is soft when dry and has platy and granular structure. Their subsoil is reddish-brown and very hard when dry. It has blocky structure. Their substratum is red, slightly hard when dry, and massive. Bedrock is at a depth of 66 to 150 cm (26 to 60 inches). In most places these soils contain small amounts of rounded gravel.

Sponseller Series

The Sponseller series consists of deep and moderately deep, well-drained, noncalcareous soils on gently sloping to steep side slopes of cinder cones. These soils formed in material weathered from volcanic cinders. They occur in the pine forest in the eastern part of the watershed, at elevations of 2,379 m (7,800 ft) or more, where the average annual precipitation is 560 to 600 mm (22 to 24 inches). They adjoin Brolliar and Siesta soils. The overstory consists of good stands of ponderosa pine, limber pine, Douglas-fir, aspen, Gambel oak, and New-Mexican locust. The ground cover is chiefly Arizona fescue, junegrass, mountain muhly, and blue grama.

Sponseller soils have a stony, dark reddish-brown surface layer that is hard when dry and has platy or granular structure. Their subsoil is reddish-brown, is hard when dry, and has blocky structure. Their substratum is gravelly and yellowish red, hard when dry, and massive. Volcanic cinders occur at a depth of 50 to 130 cm (20 to 52 inches). In most places a thick mat of needle litter overlies the mineral soil. There are a few stones and cobblestones and a little gravel. These soils are slightly acid or neutral.

Springerville Series

The Springerville series consists of moderately deep and deep, well-drained soils on the Coconino Plateau. The slope ranges from level to steep, and the topography from smooth and undulating to rough. These soils developed in material weathered from basalt and cinders. They occurs at elevations of 1,067 to 1.982 m (3,500 to 6,500 ft), where the average annual precipitation is about 280 to 460 mm (11 to 18 inches), and are associated principally with Gem, Brolliar, and Waldroup soils. In many places they are dissected by deep canyons.

At elevations of 1,220 to 1,982 m (4,000 to 6,500 ft), the vegetation consists chiefly of pinyon pine and juniper but includes a few Gambel oaks and, on the upper reaches of these soils, scattered ponderosa pine trees. The ground cover and the understory are chiefly blue grama and black grama but include some sideoats grama, squirreltail, turbinella oak, mountain-mahogany, snakeweed, and filaree. At elevations of 1,067 to 1,220 m (3,500 to 4,000 ft), the vegetation consists of mesquite, canotia, pricklypear, filaree and tobosa.

Springerville soils have a dark grayish-brown to reddish-brown surface layer that is slightly hard when dry and has platy or granular structure. The underlying layers are brown or reddish brown, are extremely hard when dry, and break into large, blocky aggregrates. The lower layers are calcareous in most places. In some places these soils are calcareous to the surface.

Horizons are difficult to distinguish because these soils have a strong tendency to shrink and swell, and much heaving and internal movement result. When the soils are dry, they have cracks 12 to 50 mm (half an inch to 2 inches) wide and 38 to 50 cm (15 to 20 inches) deep. The cracks disappear when the soils are wet.

Selected References

Williams, J.A.; Anderson, T.C., Jr. 1967. Soil survey of Beaver Creek area, Arizona. USDA Forest Service, Soil Conservation Service, and Arizona Agriculture Experiment Station.