Palms in Biscayne National Park

Natural and artificial regeneration of an endangered palm in Biscayne National Park

Biscayne National Park holds the only natural population of Sargent's cherry palm (Pseudophoenix sargentii) in the United States. Although the species is widespread throughout the Caribbean region, its numbers have been decreasing in many of its habitats. Florida's population, located on Elliott Key, provides a unique opportunity to study and conserve this rare palm.

Since its discovery in 1886, Florida's population of Sargent's cherry palm has suffered a wide range of threats. Many trees were removed from Elliott Key for use in Miami landscapes in the early 1900s, and others perished in subsequent decades as the island was cleared for agriculture and development. Hurricanes and tropical storms caused additional casualties on the low-lying island. Historically, the species has had a very low rate of natural regeneration. Listed as an endangered species in Florida, the palm is now recovering and regenerating under the management of Biscayne National Park and its partner organizations.

Fewer than 50 individual palms remained on Elliott Key in 1991, but the population increased to more than 270 individuals by 2008. This increase was partially the result of conservation work conducted by Biscayne National Park, Fairchild Tropical Botanic Garden, and the Florida Department of Environmental Protection to compensate for the low levels of natural regeneration. Together, these organizations collected seeds from Elliott Key, grew young seedlings in Fairchild's nursery, and replanted young palms back into the wild. A total of 62 young Sargent's cherry palms were planted on Elliott Key between 1991 and 1993, more than doubling the size of the population. Many of those young palms survived and are now growing slowly toward maturity.

Natural processes have also contributed to the increase in the Elliott Key population of Sargent's cherry palm. Surprisingly, some of the wild palms that existed prior to replanting have recently produced large quantities of seeds. As those seeds germinated, we have seen a natural increase in the number of young palms on Elliott Key.

Sargent's Cherry Palm Collecting DNA from Sargent's Cherry Palm
Sargent's cherry palm (Pseudophoenix sargentii) Sandra Namoff, Fairchild's Research Technician, collecting a DNA sample from a young Sargent's cherry palm

A genetic study of the palms of Elliott Key found that the replanted palms and the naturally germinated palms have both contributed significantly to the health of the population. The DNA research, conduced by scientists at Fairchild and Biscayne National Park, showed that both sets of young palms will be effective for maintaining the genetic diversity of the population into the future. This diversity may help the species withstand future environmental changes.

Based on results from the DNA research, we will continue to use a combination of artificial and natural methods to increase the size of the Sargent's cherry palm population on Elliott Key:

  1. Promote natural seedling establishment-- Park managers are maintaining an environment on Elliott Key that will foster continued growth of young palms.
  2. When necessary, continue replanting to increase population size-- When natural regeneration is low, young palms should be propagated and replanted to mimic the effects of natural processes.