Besides the major exotic plant species Melaleuca and Brazilian Pepper, there are many species known to naturalize in South Florida. Man has brought numerous exotic plants into the Preserve to produce fruit, landscape homes and camps, and perform other functions such as providing windbreaks or preventing soil erosion. Some of these species have escaped from cultivation and are now naturalized in the Preserve. It is not always easy to decide whether a species is native or exotic. The term exotic is generally used to refer to plants which have arrived in a new area through the assistance of man; however, this is often impossible to determine.
There is a tendency to regard those which have been known in Florida for a couple of hundred years as natives and those that have been recorded only recently as exotics. Hence, water lettuce, Pistia statiotes, an Old World species present in Florida prior the the 1700's , papaya, Carica papaya, first noted here in the late 1700's, and guava, Psidium guajava, introduced prior to 1765, are usually treated as natives. Exotic plants are displacing native vegetation and destroying habitats needed for ecosystem health. In the Preserve, the melaleuca tree occupied more than 186 square miles of wetlands. The tree grows in dense monocultures completely replacing native vegetation. Melaleuca is spreading in south Florida at an alarming rate and has the potential to invade all of south Florida's wetlands within the next 50 years. The Addition Area acquisition creates an additional challenge to control a greater area of melaleuca trees and other invasive exotic species including java plum (Syzygium cuminii), tropical soda apple (Solanum viarum), old world climbing fern (Lygodum microphyllum), and the Brazilian pepper tree (Schinus terebinthifolius).In the Preserve, an integrated pest management program has been in place since 1984 and has resulted in the treatment of over 14 million melaleuca "stems" at a cost near $6 million. An off-site partnership mitigation project with Dade County has provided $1.5 million of the cost for the treatment of 200,000 acres within the Preserve through calendar year 2001.All south Florida governmental entities support and fund programs to remove invasive exotic plants. Exotic plant control also receives avid support from a host of local organizations including the Tropical Audubon Society, The Sierra Club of Miami, The Everglades Coordinating Council and Outward Bound. National Park Service (NPS) management policies mandate the control of exotic plants including total eradication if the exotic species threaten protection or interpretation of resources being preserved. Without adequate control invasive exotic species threaten the biological integrity of Big Cypress National Preserve and the greater south Florida ecosystem.