Pine Rocklands

Pine rockland is a savanna-like forest on limestone outcrops with a single canopy species, South Florida slash pine, and a diverse understory of shrubs and herbs. It is a fire-maintained community requiring periodic burns every 3 to 7 years (Snyder et al. 1990). This community is often found in association with rockland hammock and short hydroperiod freshwater wetland communities.

The flora of pine rocklands is influenced by the community's proximity to the tropics as well as its peninsular connection to mainland Florida (Robertson 1953, Snyder 1986, Snyder et al. 1990). K. Bradley and R. Hammer (unpublished data) have recorded 374 native plant taxa in pine rocklands of Miami-Dade County, outside of Everglades NP. Although species diversity and richness varies geographically for pine rockland communities, the Richmond tract in Miami-Dade County contains 260 taxa of native plants (DERM 1994), the Navy Wells Pineland Preserve contains 172 taxa, and the Tamiami Pineland Preserve contains 163 taxa.

A high degree of vascular plant endemism is observed in the pine rockland community. In a 1977 survey of the 186 species noted in Miami-Dade and Monroe county pine rocklands, 30 species were only found in pine rockland communities in Miami-Dade County (exclusive of Everglades NP), and nine of these were endemic to the pine rockland community (Loope et al. 1979). Approximately 31 plant taxa which occur in pine rocklands are currently treated as endemic to South Florida (Table 1); 13 of these taxa occur in additional plant communities such as marl prairies or rockland hammocks (e.g. Blodgett's wild-mercury (Argythamnia blodgettii) , pineland clustervine (Jacquemontia curtissii), and false-leadplant (Dalea carthagenensis var. floridana)). Many taxa which were formerly considered to be endemic have been found in other regions such as peninsular Florida, the Bahamas, or Cuba [ e.g. Blodgett's ironweed (Vernonia blodgettii), Florida gamagrass (Tripsacum floridanum) , Florida white-tops (Rhynchospora floridensis)], or are no longer considered to be taxonomically distinct (e.g. Polygala boykinii var. sparsifolia), and pineland-privet (Forestiera segregata var. pinetorum).

Many plant taxa reach their northern or southern limits in the pine rocklands of South Florida. Taxa with their entire United States distribution in South Florida which are limited to pine rocklands include Bahama sachsia (Sachsia polycephala) , pineland daisy (Chaptalia albicans) , quailberry (Crossopetalum ilicifolium), and shrub eupatorium (Koanophyllon villosum). A number of species in pine rocklands are disjunct from sandhill communities in central Florida. These include Asclepias viridis, Cyperus filiculmis, Desmodium marilandicum, dollarweed (Rhynchosia reniformis), Gray's beakrush (Rhynchospora grayi) , green-eyes (Berlandiera subacaulis) , Rhynchosia michauxii, Tracy's bluestem (Andropogon tracyi) , and Zornia bracteata . These taxa are primarily found in deposits of sand in the northern Biscayne pinelands, although Asclepias viridis can also be found on Big Pine Key.

The overstory of pine rocklands is open and dominated by a canopy of South Florida slash pine ranging in height from 20 to 24 m (65.6 to 79.2 ft) (Snyder et al. 1990). In the lower Keys the pine trees are smaller and the subcanopy includes Thrinax and Coccothrinax . Slash pine densities in pine rocklands have been reported at 453 to 1,179 pines/ha (185-477 pines/acre) on Long Pine Key (Snyder 1986), and 90 pines/ha (36 pines/acre) in the Turner River Area of Big Cypress National Preserve (Gunderson et al. 1982). This canopy provides a source of pine needles for fine fire fuel. The pine canopy ignites rarely, typically after long periods of fire suppression. Germination occurs during October, November, and December, with survival highest when optimal soil moisture is present the following dry season (McMinn 1970). The seedlings remain in the grass stage for 2 to 5 years. Growth occurs over a period of approximately 10 months from February to November (Langdon 1963). There is little to no subcanopy. However, hardwoods that may occur in the subcanopy include live oak (Quercus virginiana), wild-tamarind (Lysiloma latisiliquum), and willow-bustic (Sideroxylon salicifolium). These species are more abundant in areas where natural fire is suppressed (Snyder et al. 1990, DERM 1995) and in pine rocklands in close proximity to tropical hardwood hammocks (Loope and Dunevitz 1981).

Taken from: U.S. Fish and Wildlife Service. 1999. South Florida Multi-Species Recovery Plan. Atlanta, Georgia. Pp. 3-162, 3-164.

Listed Species Occurring in Pine Rockland Habitat

  • Key Deer
  • Kirtland's Warbler
  • Bald Eagle
  • Eastern Indigo Snake
  • Florida Panther
  • Garber's Spurge
  • Deltoid Spurge
  • Tiny Polygala
  • Small's Milkpea
  • Crenulate Lead Plant