Longleaf Pine

Description

Longleaf pine is an evergreen conifer that got its common name for having the longest leaves of the eastern pine species. The needlelike leaves, which come in bundles of three, can grow up to 18 inches (46 centimeters) long. Mature trees stand 80 to 100 feet (24 to 30 meters) tall. The single trunk, which is covered in thick, scaly bark, reaches up to three feet (0.9 meters) in diameter. The trees naturally prune their lower branches and grow almost perfectly straight.

Range

The historic range of the longleaf pine once extended from southeastern Virginia to Florida, west through Louisiana to east Texas. Today the trees are only found within small patches of this range. Longleaf pines can survive in a range of habitats, but they prefer sandy, dry, acidic soils ranging in elevation from sea level to 2,300 feet (700 meters). They are intolerant to shade and require sunlight to grow. When frequent fires sweep the forest, longleaf pines dominate and sometimes form pure stands.

Life History

Longleaf pine seeds develop in cones and are dispersed by wind. When they fall to the ground, they must come in contact with soil to germinate. Historically leaf litter and debris were cleared away by forest fires that were sparked during lightning storms. When fire is suppressed, ground cover buildup prevents seeds from reaching the soil, and they can’t germinate. The seeds that are able to take root undergo an interesting life cycle that differs from most other conifers. Rather than spending its first few years growing in height, the longleaf pine goes through a grass stage.

From the surface, the grass-stage plant appears to be a large clump of needles that grows very little. The real work, however, is going on underground. During the grass stage, the longleaf pine starts to develop its central root, called a taproot, which will be up to 12 feet (3.7 meters) long at maturity. After going through the grass stage, longleaf pines begin to grow in height. Both mature trees and grass-stage specimens are fire-resistant. The lifespan of a longleaf pine spans several centuries. These slow-growing trees live for over 300 years, and they may take up to half that time to reach their full size.

Conservation

Longleaf pines, which once covered an estimated 90 million acres, now cover less than 3 percent of their original range. This tree was once so abundant that it seemed like an inexhaustible resource to early settlers. Forests of longleaf pines were cleared to make space for development and agriculture. The lumber, which is of exceptional quality, was used for building ships and railroads. Most of the longleaf pines were gone by the 1920s, and they had a hard time coming back on their own because of fire suppression. Rather than replanting the longleaf pines, foresters replaced them with faster-growing pines that would produce more short-term economic benefits.

Restoration of longleaf pine forests has become a major conservation priority in recent years though. More than 30 endangered and threatened species, including red-cockaded woodpeckers and indigo snakes, rely on longleaf pines for their habitat. Additionally, longleaf pines are more resilient to the negative impacts of climate change than other southeastern pines. They can withstand severe windstorms, resist pests, tolerate wildfires and drought, and capture carbon pollution from the atmosphere. A number of nonprofits, government agencies, and private landowners are collaborating to restore longleaf pine forests.

Fun Fact

The southern longleaf pine (Pinus palustris Miller) is the state tree of Alabama.

Sources

University of Florida

USDA Natural Resources Conservation Service

U.S. Fish & Wildlife Service

U.S. Forest Service