Botany: Florida Climate & Biogeography

Florida’s overall climate pattern

Subtropical overall, temperate in the north, tropical in the south

Major system influencing Florida weather

The Bermuda High controls storms and rainfall patterns

Bermuda High effect on fall and winter weather

Prevents convective clouds and thunderstorms until it weakens in late spring or early summer

Bermuda High influence on hurricanes

Steers hurricanes along its edge and can push storms toward the Gulf

Cause of rapid weather shifts from late fall to early spring

Cold fronts that force warm air upward, producing storms and temperature drops

Factor determining winter cold front penetration

Jet stream position

Season with largest temperature extremes and drought risk

Spring

Key summer weather characteristics

Long days, high temperatures, high humidity, and high rainfall

Role of sea breezes in summer storms

Temperature differences create rising air and convective storms, reversing at night into weaker land breezes

Rainfall pattern during fall

Rainfall decreases significantly and November is typically the driest month in central and northern Florida

Characteristics of Florida freeze events

Short duration freezes with north or northwest winds that recur roughly every decade

Reason Florida is closely tied to the sea

Low elevation and no point more than 100 kilometers from saltwater

Age and type of oldest terrestrial sediments

Marine sediments about 25 million years old

Main factors complicating Florida biogeography

Climate boundary, long peninsula shape, humid climate, open north and closed south, and changing land size and shape

Florida’s position in the Paleozoic

Part of Gondwanaland and attached to Africa

Evidence of Gondwanan origin

Pollen fossils resemble African species more than North American species

When Florida joined Laurasia

During the breakup of Gondwanaland in the Mesozoic

Sediments formed in Jurassic and Cretaceous

Shallow marine carbonates, marine clays and sands, and thick chalky limestones

Early Cenozoic environment

Shallow marine conditions dominated by seagrass with limited emergent land

Late Eocene geological change

Appalachian uplift that increased sediment deposition and left Florida submerged again

Biotic conditions in the late Oligocene

First return of major terrestrial flora and fauna and high biological richness

Time periods with major fossil gaps

Early Miocene, Middle Miocene, and Early Pliocene

Dominant Miocene vegetation

Deciduous forest, grassy savannas, and abundant fan palms

Major Miocene ecosystems

Low hammock, sandy strand, and semi-swamp palmetto brake

Common Miocene plant genera

Ulmus, Carpinus, Ficus, Diospyros, Bumelia

Pliocene faunal trend

Migration of animals into Florida via a developing land connection

Pleistocene habitat shifts

Expansion of longleaf pine savannas and repeated shoreline changes

Late Pleistocene to Holocene flora

Sand pine, oak and hickory forests, sandhill and prairie communities

Primary sources of parent material

Marine sediment buildup and sediment from the Appalachians

Reason sinkholes are common

Abundant surface limestone, high aquifer, and underground cave development

Number of USDA soil orders in Florida

Seven

Definition of Histosols

Organic, poorly drained soils typical of marshes and swamps

Definition of Spodosols

Sandy, acidic soils with a leached E horizon common in flatwoods

Definition of Ultisols

Weathered red clay soils with low base saturation found in humid regions

Definition of Entisols

Young soils with little profile development found in sandy or recently exposed areas

Western Highlands ecosystems

Forests on ultisols and sandhill or scrub on entisols

Central Ridge ecosystems

Sandhill and scrub on entisols and hardwood forest on alfisols and ultisols

Flatwoods soils and ecosystems

Spodosols that support flatwoods, prairie, ponds, and cypress domes

Organic-origin soil ecosystems

Histosols that support marshes and swamps

Recent limestone soil ecosystems

Entisols that support rockland communities

Coastal soil ecosystems

Entisols and histosols supporting beaches, dunes, maritime hammock, mangroves, and salt marsh

Effect of geologic history on ecosystems

Limestone origin created nutrient-poor sandy soils and shifting landforms shaped changing habitats and species distributions