April 1998
Mitigation funds boost melaleuca control efforts
Crews hired during 1997 cut and treated
more than 3.4 million melaleuca trees in
Big Cypress National Preserve. Retreatment,
the second phase of the melaleuca control
project, will begin in early 1998.
In unusual partnership between Big Cypress National Preserve and Dade County (Miami) has provided NPS resource managers in South Florida with funds to fight the spread of the invasive nonnative plant, melaleuca. To mitigate the effects of the development of a new jail facility, Dade County contributed $1,581,000 to be used for treatment, retreatment, and subsequent monitoring and evaluation of melaleuca infestations occupying 35 square miles in the preserve. In 1997, private contractors completed the initial treatment of the project area. The second phase of the project, retreatment, will begin in early 1998. Melaleuca is an Australian tree species that was introduced into South Florida in the early 1900s as an ornamental and a possible source of lumber. An aggressive, invasive plant, it has now spread throughout the region, displacing native plant communities with dense single-species forests that provide little value to wildlife. Experts agree that the spread of melaleuca constitutes one of the most serious threats to the greater Everglades ecosystem, which includes Big Cypress National Preserve and Everglades National Park.
Melaleuca has several characteristics that have helped it spread throughout South Florida. Rapid growth, fire-insulating bark, a damage-triggered seed release mechanism, storage of millions of seeds on a single tree, the ability to sprout from stumps and stems, and a lack of insect pests are all hallmarks of its remarkable success. Natural and prescribed fires in South Florida also favor the proliferation of the species. Fire promotes seedling establishment, and high fire intensities lead to the demise of less fire-adapted native species. In 1979, varying densities of melaleuca infested an estimated 60 square miles of Big Cypress. By 1992, systematic reconnaissance flights revealed 186 square miles of infestations. In 1984, the preserve initiated a nonnative plant control program, with primary emphasis on melaleuca. From 1984-95 NPS crews spent nearly all of their time treating outlying populations of the invasive species. The goal of this strategy was to limit the further spread of melaleuca. This strategy did not address the dense single-species melaleuca forests, which are extremely costly to treat.
With the new funding source from the Dade County partnership, Big Cypress has been able to pay private contractors. This approach has reduced the cost of treatment from 66 cents per tree to 24 cents each and has allowed the park to deal with a much larger area of infestation. The first phase of the new project resulted in the treatment of 3,420,741 trees and 957,539 seedlings at a cost of $900,000 in an area of nearly 34 square miles. To date, through the combined efforts of NPS crews and private contractors, over six million melaleuca trees on over 100 square miles have been treated. Habitat restoration projects on a scale such as this are essential to preserving natural areas threatened by nonnative pest plants.
Related Articles;
National park celebrates death of its last melaleuca tree
Related Links;Melaleuca quinquenervia
http://aquat1.ifas.ufl.edu/melainv.htmlInvasive Species: Melaleuca profile
http://www.invasivespecies.gov/profiles/melaleuca.shtmlExotics in the Everglades
http://www.nps.gov/ever/eco/exotics.htm