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Alabama's Diverse Forests

Alabama is home to one of the United State's largest forests. Sixty-nine percent of the state is covered in forest land. That's over 23 million acres! Alabama doesn't just have a lot of trees, it houses some of the most diverse organisms in the United States as well. This is due to Alabama's many physiographic regions.

Alabama's Physiographic Regions

Alabama's basic physiographic regions include:

  • Plateau – limestone valleys and uplands with rolling hills.
  • Ridge and Valley – steep ridges with little to no soil and low productivity and fertile alluvial soils in valleys.
  • Piedmont – gently rolling to steep topography with highly erodible, productive soils.
  • Upper Coastal Plain – deep, well-drained soils with low fertility.
  • Lower Coastal Plain – most of southern portion of Alabama characterized by sandy soils.

Physiographic Regions

Each of these regions is characterized by unique features. Physiographic regions are most commonly influenced by:

  • Topography
  • Soil
  • Climate
map of the physiographic regions of Alabama, including the Highland Rim, Cumberland Plateau, Alabama Valley and Ridge, Piedmont Upland, and the East Gulf Coastal Plain. Many subregions are also listed.
Courtesy of Alabama Maps, Cartographic Research Laboratory at the Department of Geography, The University of Alabama. See larger version of the Physiographic Regions map here.

Topography

Topography describes the natural features of the land. These natural features are molded and shaped by natural occurrences over time. These topographic regions vary greatly as you work across the state. The northeast portion of the state sits at the foothills of the Appalachian Mountains while the southwest portion of the state consists of beautiful white sandy beaches. The land in between is equally as diverse and provides habitats for numerous forest types and organisms.

map of the topography and elevation of Alabama including with the elevation ranges of 0 feet to 100 feet, 100 feet to 250 feet, 250 to 500, 500 to 750, 750 to 1000, 1000 to 1500, and 1500 to 2500 feet. In general the southern and south eastern portions of the state have the lowest elevations, with elevation increasing as you move north. The northeast corner of the state of alabama has the highest elevation as you move into the foothills of the Appalacian Moutains.
Courtesy of Alabama Maps, Cartographic Research Laboratory at the Department of Geography, The University of Alabama. See larger version of the Topography: Elevation map here.

Soils

Alabama is home to six distinct soil areas, each with unique characteristics. Soil is the medium for plant growth and different plants and trees thrive in each of these diverse soils. This contributes to the many different trees that can be found across Alabama.

map of the general soils of Alabama including limestone valleys and uplands, appalacian plateau, piedmont plateau, prairies, coastal plains, major flood plains and terraces, and coastal marshes
Courtesy of Alabama Maps, Cartographic Research Laboratory at the Department of Geography, The University of Alabama. See larger version of the General Soils map here.

Soils are made up of four distinct compounds:

  • Mineral particles
  • Organic matter
  • Water
  • Air

Each soil's physical and chemical properties contribute to what trees will thrive in that habitat.

four layers of ground, including soil and grass, shown separated into different materials

Climate

Climate is the third major contributing factor in Alabama's diverse forest types. The amount of precipitation and the average temperature in an area play key roles in the organisms that are present in a given environment.

map of Alabama temperature zones in degrees Fahrenheit. The divisions are greater than 68 degrees, 66-68 degrees, 64-66 degrees, 62-64 degrees, 60-62 degrees, and less than 60 degrees. The average annual temps generally go from highest near the coast at the southern end of the state and decreasing as you move farther north.
Courtesy of Alabama Maps, Cartographic Research Laboratory at the Department of Geography, The University of Alabama. See larger version of the Average Annual Temperature, in degrees Fahrenheit map here.

Forest Types

Physiographic regions influence the forest types we have here in Alabama. The five major forest types are:

  • Oak-hickory
  • Oak-pine
  • Loblolly-shortleaf pine
  • Longleaf-Slash pine
  • Oak-gum-cypress
map of Alabama forest types, including longleaf-slash pine, loblolly-shortleaf pine, oak-pine, oak-hickory, oak-gum-cypress, and non-typed less than 10% forest.
Courtesy of Alabama Maps, Cartographic Research Laboratory at the Department of Geography, The University of Alabama. See larger version of the Alabama Forest Types map here.

Oak-Hickory Forest

Oak-Hickory forests are located in the northernmost part of the state. These hardwoods are very resilient and tolerant to diverse climates. These trees are tolerant to fire, drought, and cold temperatures. These forests are home to various wildlife species as well due to the mast(fruit or nut bearing) producing trees.

an aerial view of an oak-hickory forest during autumn

Oak-Pine Forest

Oak-Pine forests serve as a transition from the oaks and hickories of the north to more pine dominated forest types. These trees are moderately tolerant to shade and often result from disturbances to the land.

forest
"Oak/pine forest (with a birch tree thrown in)" by jmlwinder is licensed under CC BY 2.0.

Loblolly-Shortleaf Pine Forest

The loblolly-shortleaf pine forest consumes the largest area of the state and can be found commonly throughout a large portion of the state. This is due to its ability to establish and grow quickly making it ideal for landowners who want to have several harvests in their lifetime. These trees are also very tolerant to the hot temperatures in our state, plus they are very tolerant of fire, making them easier to manage.

a view looking directly up through the canopy of some trees

Longleaf-Slash Pine Forest

Longleaf and Slash pines do incredibly well in sandy soils which make them ideal for the southernmost part of Alabama as we transition to the beaches of Baldwin and Mobile county. They are also incredibly drought and heat tolerant.

Naturally regenerated Longleaf Pines in the DeSoto National Forest in Mississippi. "Longleaf Pine" by Woodlot is licensed under CC BY-SA 3.0.

Oak-Gum-Cypress Forest

Oak, Gum, and Cypress forests are not as tolerant as our pine forests, but they can handle very wet, poorly drained soils. This means they can be found along our major waterways such as the Tombigbee and Alabama Rivers, which are tributaries of the Mobile River that flows into Mobile Bay.

a creek running through a forest