A. GENERAL INFORMATION:

Project Title: Fire Ecology of South Florida Wetlands
Project Start Date: 1996 Project End Date: 2004
Project Funding: USGS Place-Based Studies Initiative
Principal Investigator: James R. Snyder
Email address: jim_snyder@usgs.gov
Phone: 239-695-1180 Fax: 239-695-1137
Mail address: USGS, Big Cypress National Preserve Field Station, HCR 61, Box 110, Ochopee, FL 34141

Project Summary: Prescribed fire constitutes one of the most pervasive management actions influencing the restoration and maintenance of the Greater Everglades Ecosystem. It is generally assumed that lightning-ignited fires were common at the beginning of the rainy season, but there have probably been human-caused fires at other times for the last several thousand years. Since lighting-ignited fire cannot be allowed to operate naturally in South Florida, prescribed (or management-ignited) fire must be used to maintain these habitats. The seasonal occurrence of fire can have an important influence on ecological responses. We have conducted a set of experimental studies to determine the response of vegetation to different seasons of burning.

Project Objectives and Strategy: The project objective is to determine the importance that season of burning has on the response of vegetation to fire. We have addressed this through the use of experimental prescribed fires at different times of the year. In Big Cypress National Preserve we have established a long-term study of season and frequency of burning in the unlogged hydric pinelands of the Raccoon Point area. This study includes three seasonal treatments: winter (dry season), spring (early wet season) and summer (mid wet season). A shorter study comparing the response to winter and summer burns was carried out in the pine rocklands on Big Pine Key. We are also studying the effect of season of burning on muhly grass (Muhlenbergia filipes), a component of hydric pinelands and often a dominant in short-hydroperiod wetlands known as muhly or marl prairies. We are conducting field and nursery studies to determine how the season of burning effects the rate of recovery of muhly and its ability to tolerate flooding.

Potential Impacts and Major Products: The results of this work will influence the fire management of the publicly owned lands in the Greater Everglades ecosystem. Major products include a publication on the unique vegetation of the unlogged hydric pinelands in Big Cypress, which will serve to document the initial conditions of a long-term study of season and frequency of burning; a publication on the effects of fire on pine rockland understory vegetation structure and diversity; management recommendations for prescribed burning of Lower Florida Keys pinelands; and a paper on the response of muhly to flooding after burning at different seasons.

Collaborators: National Park Service, FIU (Drs. Ross and Koptur)

Clients: National Park Service, Fish and Wildlife Service

B. WORK PLAN

Title of Task 1: Season of burning in South Florida pinelands
Task Funding: USGS Place-Based Studies Initiative
Task Leaders: James R. Snyder
Phone: 239-695-1180
FAX: 239-695-3007
Task Status: active
Task priority: High
Task Personnel: To be hired

Task Summary and Objectives: This task involves comparing experimental burns at different seasons in Big Cypress National Preserve (hydric pine flatwoods) and Big Pine Key (pine rocklands) to see if there are there are detectable differences in the response of the vegetation.

Work to be undertaken during the proposal year and a description of the methods and procedures: The fieldwork has been completed and the work will consist of data analysis and reporting. The experimental burns for the long-term study of season and frequency will continue to be carried out by the Big Cypress NPS fire management staff. If a source of subsidized labor is available (perhaps NPS fire crew or SCA interns), all 54 permanent tree plots will be revisited and tree diameters remeasured. The trees were last measured in 1995.

Planned Outreach: Will help organize and participate in a South Florida slash pine symposium. A refereed journal article will be submitted on the initial vegetation conditions of the long-term study plots in Big Cypress and the data will be made available through USGS. For the Big Pine Key study, manuscripts will be prepared with collaborators from FIU on fuel loads along a chronosequence of time since last fire, effects of fire on understory vegetation structure and species diversity, and prescribed burning: a management tool in the slash pine forests of the Florida Keys.

Title of Task 2: Seasonal fire effects on muhly grass
Task Funding: USGS Place-Based Studies Initiative
Task Leaders: James R. Snyder
Phone: 239-695-1180
FAX: 239-695-3007
Task Status: active
Task priority: High
Task Personnel: To be hired

Task Summary and Objectives: Muhly grass is a component of hydric pine forests and short hydroperiod prairies, including the habitat of the Cape Sable seaside sparrow. Fire is a natural and necessary phenomenon in prairies, and the interaction of fire and flooding can have profound effects on vegetation. Our objective is to address two questions relevant to fire management and the endangered Cape Sable seaside sparrow: 1. How does season of burning effect the rate of recovery of muhly?, and 2. How does season of burning effect the ability of muhly to tolerate flooding?

Work to be undertaken during the proposal year and a description of the methods and procedures: Experimental studies have been established at 3 sites in Big Cypress. A large number of marked muhly individuals were burned over a 6-month period beginning January 2003 and the height of regrowth is measured periodically. Measurements will continue monthly until May 2004. Flowering culms will be counted in October. A companion study utilizing potted plants and large tubs was also set up. Some plants were burned periodically over a five month period. This June the plants were placed in large tubs in which water levels are maintained either at the ground surface, 10 cm above the ground surface, or 20 cm above the ground surface. Water levels will be dropped beginning in September. The height of the regrowth is measured periodically and the aboveground biomass will be harvested in May 2004.

Planned Outreach: The final report will be submitted to the NPS and a journal article describing the study will be submitted for publication.

C. BRIEF DESCRIPTION ON HOW PROJECT TASKS SUPPORT THE DOI AND USGS EVERGLADES RESTORATION SCIENCE PLANS