 |
Bougainvillea
arbor above Flamingo
Lake on November 2001 with only
a few large planted trees |
The creation
of a lush tropical jungle in two years from a barren semi-tropical site
requires the coordination of input from a number of disciplines. Horticulture,
Landscape Architecture, Civil Engineering, and Soil Science are a short
list of the entities needed for the success of such an undertaking.
Initially
a planting plan must be put into place that not only includes the immediate
design but also takes into account the natural evolution of a tropical
forest and the purpose of the creation of this "Jungle". Every
site poses its own unique conditions, many of which only become apparent
during the construction or installation process.
The plan
to create a "Jungle" on Watson Island is a plan in flux, which
allows flexibility in decision making when certain conditions become apparent
during the plant installation and growing process. An Integrated Pest
Management (IPM) program must be started that will effectively direct
cultivation techniques, irrigation, and soil management. The IPM program
will determine the long term maintenance and success of the landscape.
The original
method behind the creation of the planting plan on Watson Island was to
parallel a natural renewing process similar to forest regeneration after
a tree-fall or a catastrophic event like that of a destructive hurricane
on a natural forest ecosystem. This plan was, in part, based upon the
successful reconstruction and replanting of Parrot Jungle and Gardens
natural hammock after Hurricane Andrew in 1992. There are many similarities
between the two events. The major parallels are full sun, few or no canopy
trees, no irrigation system, a foliage understory to replant or create,
and very little time to restore or create the "Jungle". It always
critical to open (or reopen) a facility for business when the major source
of revenue is the paying customer.
Sunlight
is a critical component of growing tropical plants. More sunlight means
a more colorful garden because blooming is most often stimulated by light
in many species of tropical plants. Plants will also tend to grow more
compact and symmetrical lending a more balanced look to what otherwise
could seem wild and unkempt to the casual onlooker. In a tropical park
setting there are other considerations to sunlight that become apparent
when considering the comfort of the facilities' visitors. Excessive sunlight
can mean excessive heat for visitors and animal inhabitants alike.
Just as in
a natural tropical forest, a continuous and high tree canopy can provide
temperatures at ground level 15 to 20 degrees F. below the temperature
at the point where the sunlight meets the top layer of foliage on the
tree canopy. When the tree canopy eventually grows together, a very shaded
and comfortable understory is provided, however this means less sunlight
for the understory plants and therefore less color. A balance must be
maintained between shade and light. The initial installation of the 60
canopy trees on Watson Island was done in a manner that takes this into
consideration.
 |
Same
Bougainvillea arbor on October
2002
with more large trees and
smaller planted foliage |
Water is
probably the most critical factor in the establishment of trees and other
plant material. Even in areas of the original Parrot Jungle where water
was only a few inches below ground level, irrigation was significant in
promoting rapid plant growth. This was especially apparent when replanting
after Hurricane Andrew. All of the areas several feet above the water
table had an irrigation system installed immediately after being cleared
of debris and replanted. The lower lying area did not have irrigation
installed and subsequently it was noticed that the plant material was
not growing as fast as that of the irrigated areas. Irrigation was then
installed and the resultant plant growth was satisfactory.
There is
no fresh water found underneath Watson Island. Municipal water is the
only source for irrigation. Mulching and the use of compost as horticultural
topdressing will be critical as a method to conserve water. The indigenous
soil on the site is mostly sand with a small organic component. The compost
adds more organic matter to the sand and will increase moisture retention.
The microorganisms in the compost also act as a nutrient sink, further
benefiting the plants and trees. The mulch will lower the temperature
to the soil thereby reducing soil evaporation. Mulch also cuts down on
weed problems in sunny areas.
Much of the
tree canopy material that is being installed on Watson Island can be placed
into one of two categories, long-lived and short-lived. Similar to what
happens when a light-gap occurs after a tree falls to the ground; the
first plants to colonize the newly lighted site are fast growing, short-lived
trees or shrubs. These plants are eventually taken over and shaded out
by slower growing but longer-lived trees. The fast growing trees being
planted at Watson Island are mostly Cecropia, Ceiba, and Pachira species.
At Parrot Jungle after Hurricane Andrew, Trema micrantha, the Florida
Trema was an important fast growing tree species utilized for a temporary
short-lived canopy.
There is
also a horizontal planting component. The different pathways, exhibits,
and buildings need to be screened from each other. While allowing for
the more colorful and ornamental plants to be viewable by the Park's visitors,
another more dense foliage barrier must be maintained behind and between
the more tender and sensitive ornamental plants. This dense foliage must
be cold and wind resistant. It must also provide a visual barrier in case
inclement weather or insect problems damage the ornamental plants. Some
of these barrier plants are Clusia rosea, the Pitch Apple, Cocoloba diversifolia,
Pigeon Plum, Calophyllum sp., and Chrysophyllum oliviforme, Satin Leaf. |