The Miami Rock Ridge is a continuous limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 outcropping which formerly encompassed a large extent of far southern Florida

Florida

Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...

, including portions of the Everglades

Everglades

The Everglades are subtropical wetlands in the southern portion of the U.S. state of Florida, comprising the southern half of a large watershed. The system begins near Orlando with the Kissimmee River, which discharges into the vast but shallow Lake Okeechobee...

 ecosystem

Ecosystem

An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....

. The traditional base of the elevation ranges from northern Miami-Dade County

Miami-Dade County, Florida

Miami-Dade County is a county located in the southeastern part of the state of Florida. As of 2010 U.S. Census, the county had a population of 2,496,435, making it the most populous county in Florida and the eighth-most populous county in the United States...

 (the approximate latitude of North Miami Beach

North Miami Beach, Florida

North Miami Beach is a Miami suburban city in Miami-Dade County, Florida, United States. Originally named Fulford in 1926 after Captain William H. Fulford of the United States Coast Guard, the city was incorporated in 1927 as Fulford, but was renamed North Miami Beach in 1931. The population was...

) southward to the upper Florida Keys

Florida Keys

The Florida Keys are a coral archipelago in southeast United States. They begin at the southeastern tip of the Florida peninsula, about south of Miami, and extend in a gentle arc south-southwest and then westward to Key West, the westernmost of the inhabited islands, and on to the uninhabited Dry...

, and it extends southwest into Everglades National Park

Everglades National Park

Everglades National Park is a national park in the U.S. state of Florida that protects the southern 25 percent of the original Everglades. It is the largest subtropical wilderness in the United States, and is visited on average by one million people each year. It is the third-largest...

 and Long Pine Key. The coastal ridge was traditionally a component of the endangered pine rocklands, which grew upon the length of the ridge. The environmental community consisted of a large and continuous expanse of South Florida Slash Pines

Slash Pine

Pinus elliottii, commonly known as the Slash Pine, is a pine native to the southeastern United States, from southern South Carolina west to southeastern Louisiana, and south to the Florida Keys....

 (Pinus elliottii var. densa), which was interspersed by subtropical hardwood hammocks. The globally imperiled pine rockland community

Community (ecology)

In ecology, a community is an assemblage of two or more populations of different species occupying the same geographical area. The term community has a variety of uses...

, which also encompassed the Florida Keys and The Bahamas, supported numerous endemic plant species; 20 percent occur nowhere else in the world. The communities of the Miami Rock Ridge are maintained by wildfires, including natural fires caused by lightning strikes; this affects the vegetation and its associated inhabitants, thus maintaining a diverse ecosystem. The substrate—often consisting of marl

Marl

Marl or marlstone is a calcium carbonate or lime-rich mud or mudstone which contains variable amounts of clays and aragonite. Marl was originally an old term loosely applied to a variety of materials, most of which occur as loose, earthy deposits consisting chiefly of an intimate mixture of clay...

—and climate also affects the height of vegetation; thus a mature subtropical hammock typically does not exceed 59 feet (18 m) on the Miami Rock Ridge. Today the original communities have been largely removed by development, and the remaining pieces of the ecosystems are scattered into tiny fragments in extreme southeast Florida; they now encompass small fractions of their original range.