Melaleuca quinquenervia: South Florida's Public Enemy #1

     Over the course of the last few weeks, I have been in the backcountry of Corkscrew treating a variety of invasive species. One particular species rests at the top of Corkscrew resource management's invasive species hit list. This particular invasive tree not only plagues landscapes locally at Corkscrew, but has an extensive and dense range throughout South Florida. The perpetrator of South Florida environmental degradation highlighted here-- Paper Tree (Melaleuca quinquenervia)-- has dramatically changed the landscapes of South Florida and affected both plant and animal communities in its wake.
 Paper tree, like most invasive species I have come across in my land management experiences, is a fairly attractive plant, with birch-like white bark and large clusters of creamy white flowers that resemble caterpillars latching onto the ends of the upper canopy. The narrow, lance-shaped leaves hang from stems in an alternating pattern, forming a pleasant array of grayish green foliage. In its native Australia, Paper Tree is a prized tree species that is valued by bee-keepers, used frequently in landscaped parks, and is a focal species for some areas' conservation efforts. Here in Florida, though, Paper Tree displaces native vegetation as a result of the tree's prolific seed production that can quickly establish large, impenetrable monocultures. These massive stands of Paper Tree additionally displace the native fauna that have evolved to depend on the shelter and food that native plants provide.
     Additionally, Paper Tree is changing the hydrology of South Florida ecosystems. The tree is able to most effectively colonize areas that contain peat soils and have a short hydroperiod (i.e. seasonal water inundation lasts only a short time). As the trees proliferate and grow taller, the continual shedding of leaves and bark creates more organic material that filters into the forest floor, creating more upland habitats and effectively drying out large areas of land.
     Paper Tree also changes South Florida's fire behavior. When Paper Tree invades habitats like sawgrass prairies, freshwater marshes or hardwood bottomlands that have evolved and adapted to a consistent fire regime, the amount of surface level fuels available for a fire to burn dramatically increases. The increase in surface fuels (i.e. leaf litter and bark from the tree), combined with the volatile organic compounds found in the tree's leaves, create fires that burn at much higher than normal temperatures, causing greater occurrences of crown fires and tree/plant mortality.
     Treatment of Paper Trees is estimated to cost the state of Florida somewhere around $2 million annually. The potential economic damage of unchecked Paper Tree infestations across South Florida is estimated to total in excess of $100 million, largely harming tourism industries linked to South Florida's public lands. Here at Corkscrew, Paper Tree is routinely patrolled for and treated with chemical methods. For as much environmental and economic damage it does, it was an especially satisfying feeling heading into the pine flatwoods at CSS and putting a halt to the spread of this sinister invasive species.

        -Hayden (Conservation Intern)