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Reintroduction of Pseudophoenix sargentii in the Florida Keys
Reprinted
with permission from the January 1995 issue of Principes, Vol
39, No 1
Journal of the International Palm Society
© 1995 The International Palm Society, all rights reserved
CAROL
LIPPINCOTT
 Fairchild Tropical Garden,
11935 Old Cutler Road, Miami, FL 33156, USA
This is an article about
restoring wild palms in their wild places. As a horticulturist, I delight
in the cultivation of palms from around the world. As an ecologist, I live
with a profound sense of loss, knowing that some palm species may exist
only in gardens, their natural habitats destroyed.
As former Curator of
Endangered Species at Fairchild Tropical Garden, I know that botanic gardens
are more than just pretty places. Palm collections such as Fairchild's provide
a tantalizing example of the diversity of palms that have evolved in dynamic
natural systems. Yet palms grown in the controlled simplicity of a garden
are at an evolutionary dead-end. Therefore, the collections and scientific
resources of botanic gardens should be used to re-establish rare palms in
appropriate natural habitats, where species can continue to evolve with
a myriad of mingling plants and animals. Reintroduction of plants into conservation
areas is becoming a more common practice in efforts to prevent extinction
of endangered species (Falk and Olweu 1992).
Transplanting of an
endangered species might take place if a site is being cleared and the plants
would otherwise be destroyed, or for restoration of a wild population that
has dwindled due to human activities. While championing endangered species
reintroductions, I do not advocate jaunts into the woods to add to the flora
to an area or to spread around species which one personally thinks should
be more abundant. The motive for reintroduction should be more than an impulsive
urge to right a wrong. Reintroduction should be a carefully planned and
documented experiment in restoring a lost or abused member species in a
native plant community. Scientific staff of The Nature Conservancy,
an international conservation organization that manages numerous nature
preserves, recently developed an elegantly simple dichotomous key to help
in deciding when species reintroductions are appropriate (Gordon 1994).
First, is the species really threatened? Are there protected populations?
Is there protected habitat within the known range of the species? Has the
original cause of species decline been identified and eliminated? Are verifiable
and legal propagules available? Is site management within the requirements
or tolerance of the species?
These questions will
be addressed in the following description of a relatively straightforward
reintroduction project for a threatened palm species in south Florida. While
not the perfect model, it is an example of a stepwise process that we hope
will result in a thriving and self-sustaining palm population in the wild.
A
Rare Florida Native: Pseudophoenix sargentii
Pseudophoenix sargentii
H. Wend. ex Sargent, the Sargent's cherry palm, was first discovered
in 1886 on Elliott Key, an island ten miles from the shores of Miami, Florida,
and was first described from specimens collected there (Sargent 1886). Soon
thereafter, Pseudophoenix sargentii was found on Sands Key, adjacent
to Elliott Key, and on Long Key, about 50 miles southwest of Elliott Key.
Even upon discovery, palm populations on these three islands were small,
from a few dozen to a few hundred palms. A thorough and disheartening chronology
of the status of this palm species in the Florida Keys, from its discovery
through the late 1950's, was published in an early Principes article
(Ledin et al. 1959) (Figs. 1,2). Hundreds of these attractive palms were
dug up from Long Key to be sold as ornamentals, and a scraggly few remained.
On Elliott and Sands Keys, all but a few of the palms were cleared for island
plantations and homesites.
Ten years after Ledin's
surveys of Pseudophoenix sargentii, the interior of Elliott Key
was bulldozed by spiteful developers just prior to federal purchase of the
island for the formation of Biscayne National Park. By 1991, when volunteers
and I had resurveyed all of the historical locations of the Sargent's cherry
palm, no palms were found on Long or Sands Keys, and fewer than fifty palms
remained on Elliott Key (for a full account, see Lippincott 1992).
The small Sargent's
cherry palm population in subtropical Florida is peripheral to the species'
wider distribution along the tropical coastlines of the Bahama Islands,
Hispaniola, Cuba, and the Yucatan Peninsula of Mexico. Throughout its range
in the northern Caribbean, Pseudophoenix sargentii is increasingly
threatened by the activities of humans. On most of the shores where it occurs,
Pseudophoenix sargentii is threatened by imminent development,
as impoverished Caribbean nations lure foreign tourists with resorts and
vacation homes. Mature palms are frequently dug from natural areas and transplanted
into gardens, with few surviving the move. In areas such as Saona Island,
a U.S. Coast Guard base where the wild palms are protected from harvest,
almost no young palms are found because feral grazers such as goats feast
on fruits and seedlings (R. W. Read, personal communication). Reproduction
of Sargent's cherry palm is also compromised by excessive fruit collection
for livestock feed. In summary, the survival of wild populations of Pseudophoenix
sargentii throughout the northern Caribbean is tenuous. In Florida,
the Sargent's cherry palm has been reduced in the last century from hundreds
of palms on three islands to a few dozen palms on one island. We decided
that this palm met the criteria of "threatened," and proceeded
to plan for its restoration on the three Florida islands where it once occurred
more abundantly.
Although I will use
the term "reintroduction" inclusively in this article, the term
is strictly defined (IUCN 1984) as the reestablishment of a species which
no longer exists at a site, as in this case, the return of Sargent's cherry
palms to Long Key, where palm harvesters had extirpated the wild population.
Since palms still exist on Elliott Key, replanting on that island is correctly
termed "restocking," and is usually done to moderate genetic risks
associated with reduced population size.
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