Different Ecosystems:

Tallgrass Prairie: Midwest | Chaparral: California & Southwest | Ponderosa Pine: West | Douglas Fir: West | Loblolly & Shortleaf Pine: South | Jack Pine: Great Lakes States

Giant Loblolly Pine trees in the South.

Loblolly and Shortleaf Pine

The two most commonly encountered pines in the Southeast today; loblolly (Pinus taeda) and shortleaf pine (P. echinata) dominate much of the abandoned farmland and production timberland outside of the southernmost portions of the region. Loblolly pine was widely planted for economic reasons throughout the 20th century, and is likely more common on the landscape now than in the historic past. Two other species of pine, longleaf (P. palustris) and slash (P. elliottii), dominate the landscape further south, from the Gulf to southern Atlantic coasts. Collectively these four Southeastern species are commonly referred to as "yellow pines." All of these species are intolerant of shaded surroundings and their seedlings require abundant light in order to grow.

These pines have moderately thick bark that helps to protect their sensitive tissues from most wildland fires. However, excessive fuel levels, as a result of a long history of fire suppression, can result in serious injury to overstory trees during wildfires. In the South, mature pine stands require frequent low-severity fires in order to exclude shade tolerant species, such as maples and sweetgum, from eventually dominating the forest and shading out young pines. Although seedling and sapling loblolly pines are sensitive to fires and can be killed if fire intensities are great enough, shortleaf pine is one of the Southeast's most fire adapted trees, having the remarkable ability to resprout if "top-killed" by wildland fire. This adaptation is not unlike that possessed by the many species of oaks and hickories naturally associated with this species throughout its range. Fire also helps to maintain pine dominance by creating an ideal seedbed for the pines' seeds. Many of the Southeast's upland plants are not only adapted to fire, but require it because fire maintains sunlit conditions at the forest's floor, removes annual accumulations of leaf litter and other debris, and recycles nutrients back into the surface layer of the soil.

Without fire in the upland forests of the southeast, pines and their associated fire tolerant hardwoods would be slowly replaced by a crowded stand of fire-intolerant species. This forest change could create hazardous conditions for wildfire, allow for increased forests diseases, and would certainly exclude many of the South's diverse plant and wildlife species.