Geological History and Current Physiography

Very diverse past and present geological influences have strongly impacted the biodiversity of the Panhandle.  The Panhandle has been slowly emerging from the sea since at least some time in the Miocene (26-6 mya).  Present day Florida is only part of a much larger unit, the Floridian Plateau, an extension of the North American continent.  However, the physical size of Florida has varied greatly throughout geological history, from being many times larger than it is today to consisting of a series of small islands (which now comprise central Peninsula scrub ecosystems).  The rocks that underlie the Panhandle range in age from Precambrian (570 mya - 4.6 bya) to recent.  The surface geology of the Panhandle is entirely sedimentary.  The Panhandle is currently divided into three physiographic regions, the Northern Highlands, the Marianna Lowlands and the Gulf Coastal Lowlands.  The highest elevation in Florida occurs in the Northern Highlands, near Florala at 345 ft.  Bluffs overlooking the Apalachicola River can be over 200 ft in height!  The Marianna Lowlands is a karst region between the valleys of the

Apalachicola/Chattahoochee, Chipola and Choctawhatchee Rivers.  The Marianna Lowlands has the highest number of dry caves (ca. 140 +) within Florida.  The Gulf Coastal Lowlands are found along the Gulf of Mexico and are generally low in elevation and poorly drained containing many wetland areas.  This lowland area contains barrier islands, lagoons, estuaries, coastal ridges, and relict spits and bars, with intervening coast-parallel valleys.

Climate

Climate is a very important factor effecting the Panhandle’s rich biodiversity.  As a result of the regions mild climate, stronger seasonal fluctuations (than the Peninsula), abundant rainfall and past climatic influences; the Panhandle supports a rich diversity of plant and animal species.  The Panhandle experiences a mild subtropical climate as a result of its latitude and a stablizing effect due to the adjacent Gulf of Mexico.  Winter temperatures are quite variable due to the frequent passage of cold fronts.  These fronts are Pacific and Arctic in origin.  Arctic fronts can lower temperatrures to 15-20 degrees F., with single digits occasionally recorded.  The Panhandle has two peak rainfall periods: a primary summer thundershower period, and a secondary winter cold front shower period.

Central Location in the Southeastern United States

Because of the Panhandle’s central location in the southeastern U.S., it receives biogeographical influence from several regions in the U.S.  The range of many species of plants and animals converge and overlap, and terminate within the Panhandle.  The Panhandle receives biogeographical influence from the Tropics (through the Peninsula), the Atlantic Coastal Plain, the Gulf Coastal Plain, and the Appalachian Mountains (from the Apalachicola/Chattahoochee Rivers).

Number of Diverse Ecosystems