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Florida Trees in the High Pine Grassland Ecosystem

Pine woodlands once covered millions of acres of the Atlantic-Gulf Coastal Plain and parts of the Appalachian flanks in the southeastern U.S. Among the many distinct pine communities are grassy upland savannas dominated by longleaf pine --- sometimes called "high pinelands" --- that historically flourished on the sandhills and clayhills of northern and central Florida. These beautiful, open tracts of generously spaced trees and groundcover grasses are threatened today due to widespread habitat modifications.

Pines
- Longleaf pine dominates upland pine woodlands and savannas across much of northern and central Florida. These conifers grow needles that may be 1.5 feet long, sported in relatively open, sparse canopies. Reddish, scaly bark cloaks the straight trunks, which, on tall pines, may soar 150 feet to the crown. Longleaf pines produce large, roundish cones that may be 10 inches long. Old veteran longleafs may be a half-century or more in age.
  
  Farther south in Florida, slash pine wholly replaces longleaf in the tropically influenced "rockland" savannas of the Miami Rock Ridge, Big Cypress and the Florida Keys. But it does mingle in the longleaf-dominated communities farther north, distinguished by its shorter needles and more ragged bark. Loblolly and shortleaf pines are other conifers regularly encountered in the longleaf uplands.
Oaks
- A number of oak species commonly grow in the high pinelands, well-adapted to the wildfire-prone landscape. Among them is the turkey oak, a shrubby tree with toothy, deeply lobed glossy leaves that sit upright on the twig.
  
  Some other pineland species don't exhibit the classic lobed foliage many in the northern U.S. associate with oaks: For example, the blackjack oak may have a round-edged leaf resembling a duck's foot, and the bluejack oak has long, slender leaves reminiscent of a willow's. Other oaks characteristic of these communities include sand post oak, southern red oak and myrtle oak.
Other Trees
- Mockernut hickory is another broadleaf tree associated with southern pinelands. Growing usually between 50 and 80 feet high and 2 feet or less in diameter, these handsome trees sport pinnately compound leaves with large, serrate leaflets. Their robust fruits, according to the authors of the "National Wildlife Federation Field Guide to Trees of North America," are the toughest to crack of any hickory nut. Other hardwoods scattered in the high pinelands include black cherry and common persimmon.
Ecology
- Fire ignited by the Southeast's generous allocation of lightning has historically helped maintain the region's pine woods and savannas at all elevations, with regular blazes occurring every few years. Mature longleaf savannas harbor widely scattered trees separated by dense beds of wiregrasses and scattered shrubs. With the fire suppression instituted in the 19th and 20th centuries, these communities are threatened by hardwood invasion and expansion: Without fire, pinewoods naturally grade into hardwood forests.

Nature