A brief history of Pine Flatwoods in South Florida
Submitted by Jerry Renick, Environmental Service Manager
Pine Flatwoods were first identified as pine barrens by William Bartram in 1791 during his travels in Florida. The term flatwoods was used by the English settlers in the early days to describe the characteristic flat ground with no topographic relief in south Florida. Slash pine (Pinus elliotti) forests have the smallest range of all the major southern pines, historically extending from South Carolina to south Florida and as far west as Louisiana.The South Florida variety (Pinus elliotti var. densa) has a natural range from just north of present day Orlando, south into the Keys and even extending into the Bahama Islands. This south Florida variety of pine is also known as yellow pine, swamp pine, and pitch pine. It is estimated that pine flatwoods as an ecosystem covered up to 50% of the land area of Florida at one time. Within these pineland communities, other habitats were included such as cypress domes, bay swamps, hardwood hammocks, freshwater marshes, wet prairies, and upland sandhills or sand pine scrub ecosystems.
Pine flatwoods are considered a type of savannah with scattered pines, scattered shrubs including saw palmetto, galberry, lyonia, cocoplum, and a few other common species. They are usually inhabited with a diverse groundcover of grasses and wildflowers. The terrain for pine flatwoods can vary greatly from its northern extent near central Florida to its southern range of Dade County, and the Keys including both the Atlantic and Gulf coastal areas. It can vary from a dry scrubby flatwoods with shrubby oaks through mesic to wet flatwoods that are similar to wet prairie.
Pine flatwood ecosystems prefer acid sandy soils that are typically low in organic material. Moisture levels are from dry to saturated, varying with the site and with yearly weather fluctuations. Flatwood plants tolerate a wide range of moisture and soil fertility. Many species may be suitable for only drier or wetter conditions. Plants are generally not tolerant of salt and shade. Under natural conditions fires occur at 1-5 year intervals, preventing natural succession to upland forest.
As the geographic area extends south, the sandy layer becomes thinner and the limestone layer becomes more prominent. This area, known as pine rocklands, is an ecosystem unique to the south Florida environment as it evolved on a limestone substrate. This ecosystem comprises the southernmost extent of the pine flatwood range and is found in the Miami-Dade County area (Miami Rock Ridge), the Big Cypress Swamp and even into the Bahama Islands. It often includes a diverse hardwood and palm understory with a very rich and diverse herbaceous groundcover. Pine rocklands are also critical foraging and nesting habitat for a diverse group of wildlife including the federally protected Key deer (Odocoileus virginianus clavium).
Another important ecosystem endemic to the pine flatwood ecosystems of south Florida is the hydric pine flatwood. This is an ecosystem that is a tale of extremes, where its characteristics and conditions fluctuate between a wetland and an upland community. This occurs due to the extremes in hydrology from the wet summer season when the South Florida region typically receives as much as 65 inches of rain or more and the dry winter and spring season where the water table can drop down to several feet below ground elevation. As a result, hydric pine flatwoods have the highest plant diversity of any habitat in south Florida.
Over the course of time, and upon settlement by Europeans several changes to the ecosystem began to occur including attempts by settlers to perform agricultural activities (livestock and crop production), clearing of forests during the Civil War period for building fortresses and barracks, construction of roads for travel created fire barriers, and introduction of non-native plant species to the ecosystem. All these activities had a negative impact on the health and stability of the pine flatwood ecosystem.
By 1841, the United States Federal Government granted each state in the union to preserve as much as 500,000 acres of land for conservation purposes. This act was in addition to the land received by the federal government as a result of the Swamp and Overflowed Lands Act of 1850. By this time, the state of Florida had 21 million acres of conservation lands. This all came in the nick of time as the 1930s brought an era that drained the Everglades and brought incredible growth to Florida for the coming decades at an average annual
rate of 4% population growth. In the last 50 years, more than 8,000,000 acres of forest lands and wetlands have fallen to development, accounting for nearly 24% the state’s land mass. Thanks to the vision of the state of Florida, Pelican Island is the nation’s first wildlife refuge, and Ocala National Forest is the first eastern United States national forest.
After preservation and conservation, the next step is restoration of pine flatwood ecosystems. This is a fairly recent activity that has had variable measures of success, although much has been learned through this process. Regular fires are essentially to the health of this ecosystem. Historically they were introduced on a 3 to 7 year cycle as a result of lightning strikes during the frequent summer thunderstorms. Today, prescribed fires are used to mimic what nature used to do on its own and is
used as a tool to maintain the vegetative community structure and keep it from transitioning to a more hardwood environment as well as controlling the encroachment of exotic and nuisance plant species. South Florida slash pine is very fire resistant, and the pine seedlings are well protected during fire events due to its long needles which shelter the apical buds from damage. Many plants in the shrub and groundcover layers quickly sprout after the fire event.
As with many ecosystems and natural lands in south Florida, the pine flatwood have been susceptible to the impacts of man since Europeans settled in North America. Through many concerted efforts, the federal, state, and local government agencies have placed thousands of acres into conservation status including upland and wetland pine flatwood ecosystems. Continued restoration efforts are a critical element in the continued attempt to preserve a diminishing and important ecosystem.