Melaleuca in the Everglades Mike Bodle Vegetation Management Division South Florida Water Management District

Early Awareness Recognized as a problem in the early 70’s (FL FWCC) Skepticism concerning ability to control

“There is very real potential that all the sawgrass in South Florida could eventually become melaleuca forest.” -Mark Maffei, 1989

“We’re basically talking everything in South Florida except the coastal ridge.” -Ted Center on melaleuca distribution in South Florida, 1989

“It’s a tree from hell.” -Dan Thayer, 1990

“Only a continued and cohesive blitzkrieg will “Only a continued and cohesive blitzkrieg will achieve solid melaleuca control.” -Mike Bodle, 1990

“Melaleuca is a biological disaster for South Florida.” -Congressman E. Clay Shaw, 1990

“Melaleuca quinquenervia is now poised to expand throughout the Everglades. The time for integrated management of the tree has come. Combined efforts and methods will, hopefully, reverse this weed’s expansion.” -Melaleuca Management Plan for South Florida, 1990

“The current level of melaleuca infestation in South Florida and the potential for continued alteration of natural habitats by this invasive biological pollutant signal that the need for a statewide melaleuca management program is now!” - Ken Langeland, 1990

“We’re getting kind of panicky, man.” -Tony Pernas, 1993

Melaleuca Management Historical Background 1975 - Two Melaleuca workshops (FL FWCC) 1980 - Melaleuca symposium (FL Div. Forestry) 1982 - Exotic woody plant conference (Fairchild) 1984 - Exotic Woody Plant workshop (ENP) 1984 - Exotic Pest Plant Council formed 1986 - ENP Initiates Control Program 1988 - EPPC Exotic Pest Plant Symposium 1990 - Melaleuca Task Force

Melaleuca Task Force January 1990 Jointly convened by Florida Exotic Pest Plant Council South Florida Water Management District >30 participants: Federal, state, & local government representatives, scientists, NGOs, private industry Objective: Develop a comprehensive strategy for managing melaleuca throughout its range in Florida

Melaleuca Management Plan May 1990 - 1st ed. April 1994 - 2nd ed. revised to include most recent information May 1999 - 3rd ed. revised to update information recommendations changed to reflect progress

Melaleuca Management Plan: EPPC Management Plan Approach Summarize current ecological knowledge identify research gaps Summarize existing control technologies what is working, and where Identify control technology research needs developing biological controls, improving chemical and mechanical controls Develop plan to integrate and coordinate efforts regionally

Melaleuca Management Plan Defining the Problem Extent of infestations: South of Hwy 60 Mainly concentrated near areas of early plantings Early Assessment: Various techniques tried satellite images false color infrared aerial reconnaissance Estimates varied 495,300 - 2.5 million acres

Melaleuca Management Plan Defining the Problem Summarize invasion of native habitats Sawgrass prairies Cypress heads Pinelands Ecological questions Reproductive ecology Florida vs. Australia

Melaleuca Management Plan Defining the Problem Summarize available control options in 1990 Many herbicides tried Effectiveness varied Initial treatments result in dense, even-aged seedling stands Treated trees often resprout Mechanical removal very expensive & unsuited for most natural areas Melaleuca tree that was controlled with herbicides surrounded by “doghair” seedlings

Melaleuca Management Plan Recommendations Research develop biological control agents search for better ways to use herbicides Develop ways to measure of infestation level fill gaps in ecological knowledge Operations Education

Melaleuca Management Plan Recommendations Research Operations establish melaleuca-free zones around ENP, Big Cypress, WCAs, Holey Land, & Lake Okeechobee apply strategy of first removing outliers, then moving progressively closer to focus of each infestation monitor sites for regrowth/seedlings up to 4 years post-treatment & retreat as needed Education

Melaleuca Management Plan Recommendations Research Operations Education inform government officials about magnitude of problem & need for funding inform resource managers of best control options & opportunities resource sharing cost-sharing inform general public of problem & encourage removal of trees on private property

Melaleuca Management Plan Implementing the Plan How quickly do infestations grow? Aerial photos of 1 mi2 areas (1:3600 scale) 8 areas in Dade & Broward Counties 25 yrs to go from 5% (30 acres) to 95% (600 acres) cover Source: Laroche & Ferriter 1992 J. Aquatic Plant Manage. 30: 62-65 1965 1990

Melaleuca Management Plan Implementing the Plan How much? Aerial surveys (SFWMD) flight lines every 2.5 mi coordinates (GPS) & density recorded for every occurrence Conducted biannually 488,000 acres in 1993 453,000 acres in 1995 391,000 acres in 1997 359,000 acres in 1999

Melaleuca Management Plan Implementing the Plan Strategy Eliminate existing stands Halt expansion mechanical removal treat with herbicides Seed/sapling mortality Reduce seed production hand-pull saplings treat with herbicides damage by biocontrol insects damage by biocontrol insects

Melaleuca Control in by Ground application in Pennsuco Mitigation Area April 1998 February 1999 October 2000 October 2001 October 2003

Melaleuca Management Plan Implementing the Plan Perform herbicide trials: Ground application Hack/squirt - completely girdle tree Cut Stump - treat stumps shortly after cut Aerial application Determine effective herbicides use microfoil boom with small (0.02) nozzle overlap spray paths by 50%

Crew Transport Airboat Helicopter – a necessity in early days of control in Everglades ATV/ Buggy

Melaleuca Management Expenditures (FY 91-01) South Florida Water Management District $21,649,322 Big Cypress National Preserve $ 2,579,000 Everglades National Park $ 3,548,000 Areas under Maintenance Control Water Conservation Areas 2A, 3A, 3B 600,000 acres Lake Okeechobee 100,000 acres Everglades National Park 200,000 acres Big Cypress National Preserve 100,000 acres

Distribution of Expenditures Ground Application 75% Aerial application 15% Biocontrol 10%

Conceptual Model Reliance Time Herbicides and Mechanical Control Biological Control Reliance Today Time

Melaleuca Management Plan Recommendations Research develop biological control agents - Yes search for better ways to use herbicides - Yes Develop ways to measure of infestation level - Yes fill gaps in ecological knowledge - Yes Operations Education

Melaleuca Management Plan Recommendations Research Operations establish melaleuca-free zones around ENP, Big Cypress, WCAs, Holey Land, & Lake Okeechobee - So-so apply strategy of first removing outliers, then moving progressively closer to focus of each infestation – Yes on most pubic lands monitor sites for regrowth/seedlings up to 4 years post-treatment & retreat as needed – Yes on most public lands Education

Melaleuca Management Plan Recommendations Research Operations Education inform government officials about magnitude of problem & need for funding - Yes inform resource managers of best control options & opportunities resource sharing cost-sharing - Yes inform general public of problem & encourage removal of trees on private property - Yes