138—North-Central Florida Ridge

This MLRA (shown in orange in the figure above) is entirely in Florida. It makes up about 2,240 square miles (5,810 square kilometers). Lake City and Live Oak are the only towns of significant size in the area. Interstate 75 crosses the entire length of this area, and it intersects with Interstate 10 at the northern end of the area. The southwest corner of the Osceola National Forest is in this area. A number of State parks are throughout the area. The Stephen Foster State Folk Culture Center is in the area.

Physiography

Most of this area is in the East Gulf Coastal Plain Section of the Coastal Plain Province of the Atlantic Plain. The southern one-quarter is in the Floridian Section of the same province and division. This MLRA is on a sand-mantled limestone upland that has an irregular, gently rolling topography. Many limestone sinkholes, some filled with water, dot the area. Only a few streams are in the area. Elevation ranges from 80 to 165 feet (25 to 50 meters). Local relief is generally 10 to 20 feet (3 to 6 meters) but can be as much as 35 feet (10 meters).

The only Hydrologic Unit Area (identified by a four-digit number) that makes up this MLRA is Suwannee (0311). The Suwannee River originates in the Okefenokee Swamp northeast of this area. It is spring-fed and flows through this MLRA. The Alapaha and Withlacoochee Rivers join the Suwannee River in the MLRA. Another Suwannee River tributary, the Santa Fe River, crosses the southern part of the area.

Geology

This area is a young marine plain underlain by Tertiary-age rocks that are primarily carbonates. Some of the oldest rocks in Florida, from the Eocene age, are at the surface at the southern end of this area. The rocks are progressively younger to the north. They include very fine grained shale, mudstone, limestone, and dolomite beds. A sandy marine deposit of Pleistocene age occurs at the surface, overlying limestone in most of the area.

Climate

The average annual precipitation in this area is 53 to 60 inches (1,345 to 1,525 millimeters). The maximum precipitation occurs in summer, and the minimum occurs in winter and late in autumn. Rainfall occurs during high-intensity, convective thunderstorms in summer. The average annual temperature is 67 to 69 degrees F (19 to 21 degrees C). The freeze-free period averages 295 days and ranges from 280 to 305 days.

Water

Following are the estimated withdrawals of freshwater by use in this MLRA:

Public supply—surface water, 0.5%; ground water, 17.9%
Livestock—surface water, 0.1%; ground water, 1.2%
Irrigation—surface water, 15.8%; ground water, 52.5%
Other—surface water, 2.1%; ground water, 10.0%

The total withdrawals average 95 million gallons per day (360 million liters per day). About 82 percent is from ground water sources, and 18 percent is from surface water sources. The abundant rainfall and the Floridan aquifer are the principal sources of water in the area. The many lakes and ponds are used for recreation. The Suwannee River has been designated as an “Outstanding Florida Water” by the State. One thermoelectric power plant uses river water for cooling. With the exception of one tributary below an active phosphate mine, the river water is suitable for almost all uses.

Shallow and deep wells in the Floridan aquifer provide water for public supply, domestic use, industry, mining, livestock, and irrigation in this MLRA. This aquifer is one of the most productive sources of ground water in the U.S. Its water is hard but of good quality. Wells yield large quantities of calcium bicarbonate type of water. The Floridan aquifer is a thick sequence of Tertiary limestone and dolomite. The Eocene Avon Park Formation and Ocala Limestone are the thickest and most productive units in the aquifer system.

Soils

The dominant soil orders in this MLRA are Ultisols, Entisols, and Alfisols. The soils dominantly have a thermic soil temperature regime, a udic soil moisture regime, and siliceous mineralogy. Well drained and somewhat poorly drained Paleudults (Blanton and Albany series) have thick sandy layers over a loamy subsoil. Excessively drained and moderately well drained Quartzipsamments (Alpin and Chipley series) are sandy throughout. Well drained, sandy Hapludalfs (Archer series), which have a clayey subsoil, and poorly drained, sandy Alaquods (Mascotte and Leon series), which have a weakly cemented layer, are less extensive in the area.

Biological Resources

This area supports open pine and oak vegetation. Longleaf pine and turkey oak are the dominant trees. Several bluestem species, Indiangrass, and several threeawn species dominate the ground cover. Hairy panicum and many sedges are in scattered areas. The MLRA also supports legumes and many annual forbs.

Some of the major wildlife species in this area are white-tailed deer, raccoon, skunk, opossum, rabbit, gray squirrel, fox squirrel, turkey, bobwhite quail, and mourning dove.

Land Use

Following are the various kinds of land use in this MLRA:

Cropland—private, 9%
Grassland—private, 21%
Forest—private, 58%; Federal, 1%
Urban development—private, 8%
Water—private, 1%
Other—private, 2%

Most of this area is in wooded farms, and some large holdings are used exclusively for forestry. Pulpwood and lumber are the principal forest products. The cropland in the area is used mainly for corn, peanuts, tobacco, soybeans, vegetables, and melons. Some hay and feed grains are grown for livestock.

The major resource concerns are maintenance of the content of organic matter and productivity of the soils, management of soil moisture, and management of animal waste. Conservation practices on cropland generally include crop rotations, cover crops, nutrient management, pest management, and irrigation water management.

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