Fire Ecology and Management of Florida Dry Prairie

Dry prairies are large treeless areas endemic to Florida.  Resembling pine flatwoods without the overstory, the treeless stature of dry prairies has been attributed to a fire regime of frequent fires.  Dry prairies were thought to have developed with a fire regime of every 1-4 years, although lower fire return intervals  (1-2 years) may have been common in regions devoid of major natural fire barriers.  Historically, most of these burns likely occurred during the late spring and early summer months (fire season) and were caused by lightening.  Anthropogenic fires expanded the season of fires in dry prairies to all seasons of the year.  Along with flatwoods, ranchers typically burned dry prairie rangeland annually or biennially during the winter or early spring months to stimulate forage growth.

Fires in dry prairie are typically intense due to the high flammability of saw palmetto and wiregrass, both of which are species that are tolerant of fire.  Dormant season burns in dry prairies favor graminoids over forb species, while burns during the growing season tend to favor forbs. Frequent growing season burns also tend to keep saw palmetto small in stature and sparsely distributed.  Fauna endemic to dry prairies have adapted to growing season burning and many ground nesting species of birds (Florida grasshopper sparrow, Bachman’s sparrow, and eastern meadowlark) will re-nest if their nest if ruined by fire.

Due to landscape fragmentation and fire suppression, the extent and condition of dry prairie has been altered considerably making this community type a priority for restoration.  Long periods (35 years) of fire exclusion can cause a loss of ground cover species, changes in pine density and recruitment, invasion of non-constituent oaks, and excessive growth of shrubs and palmetto in dry prairies. Prescribed fire is an important management tool for the restoration and maintenance of dry prairies.  Land managers can manipulate fire effects by deciding season of burn (growing vs. dormant season burns).  Prescribed burning is also used to maintain habitat for endangered animal species in dry prairies, such as the federally endangered Florida grasshopper sparrow.  In some cases where fire has been suppressed from the ecosystem, mechanical methods such as roller chopping are used in combination with prescribed burning to jump-start the restoration process.