Dry Broadleaf Evergreen Formations (DBEF)

Forest/Woodlands/Shrublands/Dwarf Shrublands

By Ethan Freid, PhD
Botanist, Leon Levy Native Plant Preserve

Coccoloba diversifolia

Alliances on a Pleistocene limestone substrate

Bursera simaruba

Alliances on a Pleistocene limestone substrate

Coccothrinax argentata/inaguensis

Woodland Alliances on a Holocene sand substrate

Coccoloba uvifera

Shrubland Alliance on a Holocene sand substrate

DBEF systems are on a limestone substrate and are a shifting mosaic of broadleaf evergreen species with areas having a local species dominant and nearby areas dominated by an entirely different set of species. In general, DBEF Tn the Bahamas is dominated by Coccoloba diversifolia (Pigeon Plum) with a suite of other species as co-dominants. Still, throughout the archipelago, there are localized areas dominated by non-Coccoloba species. These are all closed canopy systems other than in Coccothrinax sp. (Silver Top) Woodlands.  DBEF systems can be described as a shifting mosaic with different species becoming dominant or subdominant over time as different species may have differential reproductive success from environmental stressors such as disease, droughts, and/or storms.

Within DBEF systems that have not been disturbed, there can be high levels of epiphytic orchids and bromeliads. While not conclusive, a lack of epiphytes in DBEF -Forests typically indicates a history of Human Alteration to the landscape either from farming and/or fire.  In contrast, the presence of epiphytes typically indicates a lack of Human Alteration to the system.

Following rainfall and wind patterns, DBEF is taller, with a more open understory. Forests to the wetter north and shorter, denser shrublands and dwarf shrublands to the drier and windier central and southern Bahamas.  In the southernmost islands, including in the Turks and Caicos Islands, some areas experience such low rainfall and such consistent winds that the vegetation has been bonsaied and not more than one meter in height even with individuals that may be hundreds of years old.

The main variation different from the DBEF limestone community is in the central and southern islands with areas dominated by Coccothrinax argentata (Silver Top) and occurring on a sand substrate. These are areas that have largely built up since the Holocene and may still have the ridges and valleys that were formed when these areas were dunes before the beach accreted sand and moved outward over time.

In the southern Bahamas the endemic Coccothrinax inaguensis can be the dominant species. These areas are interpreted as Woodlands with the Coccothrinax as the emergent tree layer, a shrub layer, and there is no closed canopy.  Daniels (2016) reports a CoccothrinaxReynosia Alliance.

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