Description & Physiography
Although it is fragmented by three Interstate highways and the prominent, sprawling metropolitan areas of Orlando and Tampa, the Florida Peninsula also features several large managed areas that form a basis for natural resource conservation. The five largest managed areas are the Ocala National Forest (383,180 acres), Merritt Island National Wildlife Refuge (138,263 acres), Withlacoochee State Forest (128,750 acres), Green Swamp (119,365 acres) and Avon Park Bombing Range (106,110 acres). The ecoregion – and by extension, the species and communities – have been shaped by several dominant forces: pronounced wet and dry seasons, once frequent fires that swept unimpeded for miles across the landscape (and other large-scale disturbance factors like hurricanes), a high water table, and mucky or peaty soils that have developed in numerous depressional features on a karst, limestone-based substrate.
The Florida Peninsula Ecoregion has a mild climate with temperatures in the central portion typically ranging between 23 degrees Fahrenheit and 95 degrees Fahrenheit during an average year. The entire peninsula is characterized by relatively high rainfall, averaging 65 inches per year.
Plants & Animals
A large portion of the landscape supports herbaceous and forested wetlands. Upland areas in the northern portion of the ecoregion, however, include a large, although now fragmented, area of upland hardwood forest that extends southward to just north of the Tampa Bay area on the central Gulf Coast. Several ridges comprised of deep, Pleistocene-deposited sands parallel the coasts, the Brooksville Ridge on the upper west coast and the Trail Ridge and Crescent City ridges on the east coast. All of these sandy ridge systems have the longleaf pine (Pinus palustris)-dominated sandhill ecological system (one of three matrix ecological communities/systems in the ecoregion) as their primary vegetational feature.
The isolation of these small ridge tops has led to the evolution of an endemic plant and animal biota that comprises a unique community – the Florida scrub. It is estimated that 85% of the Lake Wales Ridge scrubs have been destroyed, while coastal scrubs (with many fewer endemics) are greater than 90% destroyed. The Ocala “Big Scrub” in the north-central portion of the ecoregion is largely conserved within the Ocala National Forest.
Areas of lower topography than the Pleistocene-deposited ridge systems (but not low enough to sustain marsh or swamp vegetation), include flatwoods – a matrix community characterized by a pine canopy (either longleaf pine or slash pine [Pinus elliottii – two varieties] depending upon the soils and hydrology), a thick, low shrub stratum and a highly diverse ground cover vegetation. It has been estimated that flatwoods once covered 50% of the upland Florida peninsula landscape. Along with sandhills, they are favored for housing developments. The dry prairie community – or ecological system – is also a matrix community, one endemic to the ecoregion and highly threatened with continued conversion to improved pasture and citrus cultivation.
Humans & History
Most of the land base of the peninsula is derived from sediments deposited during the interglacial periods of the Pleistocene when the majority of the ecoregion was repeatedly inundated over the previous 1.9 million years
One of the most distinctive topographic and physiographic features of the entire ecoregion is the Lake Wales Ridge, a ridge system that runs through the central portion of the ecoregion. Encompassing the highest point in the Florida peninsula, at 240 feet above MSL, the Lake Wales Ridge represents some of the most ancient land in Florida, land that was derived from the forces of marine wind and wave action as ancient beach dunes and marine terraces. Portions of the Ridge are thought to have remained continuously above sea level during the cyclic rise of marine waters during – if not substantially longer than – the interglacial periods of the Pleistocene.
Even slight changes in the relatively flat topography can dramatically influence the kind of community that develops. Several prominent ridge systems that run parallel to the coastlines feature generally infertile, moderately to excessively well-drained sandy soils. These deep sands are vitally important to the recharge of the Floridan Aquifer, a massive subterranean system of porous limestone from which the majority of Floridians derive their drinking water. Abrupt discharges from the Floridan Aquifer are also responsible for the 12 first magnitude springs (springs with a flow > 66 million gallons per day) that occur within the ecoregion.