Perhaps because its range is restricted to relatively frost-free areas of the deep South, the live oak is generally regarded as one of the archetypal symbols of the geographic region. Easily recognized by its long, sweeping limbs which are usually garlanded by beards of Spanish moss, live oak is frequently found as part of slash and loblolly pine forests. These trees share one common characteristic; that is, they all grow well in poor, sandy soils.
Live Oak Characteristics
Live oak (Quercus virginiana) is considered to be an evergreen tree, as it re-grows a new canopy of shiny, dark green leaves within weeks of the old ones falling. Initially, saplings can grow rapidly--up to 4 feet in the first year--though the growth rate declines as the tree ages. Mature specimens can reach 60 to 80 feet with crowns that spread 60 to 120 feet. The shiny, dark brown acorns reach an inch in length and are a valuable food source for turkey, bear, deer, squirrel, bobwhite and the threatened Florida scrub jay.
Live Oak Habitat
Well-drained, sandy soils are the preferred soil type for the live oak, though the tree also grows well in rich, moist soils. Live oak is highly salt tolerant; because of this, the tree appears frequently in coastal zones where ocean salt spray may pose a problem for other species. Specimens can even be found growing where its roots are flooded during high tides, though live oak does not tolerate long-term inundation. Live oak also grows in clay soils. Because of the wide range of soil types but restricted temperature zones, the range of the live oak is limited to the coastal Carolinas and most portions of states from Florida west to Texas.
Upland Pine-Oak Communities
In the coastal areas of southern states, where soils tend to be sandy and well-draining, several species of pine are the prevalent tree cover. Slash pine (Pinus elliottii) and loblolly pine (Pinus taeda) are two of the most dominant species, which grow in soils suitable for optimal live oak growth. Consequently, these trees are often occur together, growing in "communities" that may also include laurel oak, Southern magnolia and American holly.
The two main pine companion species of live oak, loblolly and slash pine, closely resemble each other but can be distinguished through the bark pattern and close inspection of their respective pinecones. Slash pine, which was once heavily utilized by naval suppliers for their valuable gums and resins, has cones of 5 to 8 inches in length and bark which forms in large, flat plates. Loblolly cones are shorter, usually from 3 to 6 inches, and which are much pricklier; loblolly bark is a darker brown and forms irregularly shaped scales.
Pests, Diseases and Intolerances
Young live oak saplings occasionally succumb to attacks by the live oak root borer (Archodontes melanopus). The main threat to live oak is present primarily in Texas, where stands of the trees are infected by a fungal infection called live oak decline. Heartwood-rot and defoliation are less common, though also caused by two separate fungal infections. The main environmental threat to live oaks is from freeze damage, though the tree is strong enough to withstand hurricane-force winds.