These data show the fire history indicator for Freshwater Non-Forested Wetlands (FNFW) through 2018.
Fire Regime is an ecological indicator for the Landscape Conservation Project (LCP) for Florida. The LCP entails a large-scale assessment of and planning for the health of important natural resources, known as Conservation Assets (CAs), in Florida. Conservation planning at the landscape scale provides a framework for safeguarding functional ecosystems, and their interconnected processes required for maintaining healthy resources. Spatially explicit data from the project informs coordination and prioritization for making conservation decisions. Additionally, a suite of ecological indicators was carefully selected for each CA to represent important characteristics of each Asset and offers metrics that serve to evaluate current status, monitor trends over time, and guide conservation activities with clear measures of management effectiveness. Results are shared routinely on the Florida Conservation Planning Atlas website (www.floridacpa.com) and periodically in a summary report card that will be available for managers and the wider public.
Fire is an important component for maintaining Freshwater Non-Forested Wetlands to sustain herbaceous plant diversity and to prevent recruitment of shrub and tree species that would alter the structure of the habitat. Fires release nutrients and increases light penetration, stimulating plant growth important for aquatic life, including fish species and wetland birds. Recommended fire regimes depend upon the type of herbaceous wetlands. For marshes, the recommended fire return interval is 3-10 years. Wet prairies have a recommendation of 2-3 years.
Fire management may be difficult to implement, however, for both financial and societal reasons. Controlled burns require significant manpower and may be deterred by presence of human development, especially high sensitivity sites such as hospitals, nursing homes, and schools. Because fire is such an important management tool, emphasis on the resources and coordination required to achieve it has become a target for LCP to stimulate the improvement in fire management of fire-maintained habitats in Florida, including the FNFW in addition to other CAs (i.e., High Pine and Scrub, Pine Flatwoods and Dry Prairie, etc.).
For these analyses, marsh and wet prairies were identified using the Cooperative Land Cover (CLC 3.3) maintained by the Florida Fish and Wildlife Conservation Commission (FWC) and the Florida Natural Areas Inventory (FNAI). The CLC identifies 247 classes of land cover in a hierarchical fashion that classifies groupings of land covers by major ecosystems, such as the Freshwater Non-Forested Wetlands.
Fire history was assessed by intersecting identified land covers with Florida's fire database. The USFWS, FWC, and Tall Timbers Research Institute worked together to develop a database of fire history for Florida. Through a combination of satellite imagery and ancillary resources (USAF Wildfire database, Florida Forest Service permitting, etc.), methods were developed to identify and validate fire histories within 10-acre hexagons dating back to 2006. Fire history metrics include fire frequency over the entire time period, time since previous fire (years), year last burned, longest fire free interval, and seasonality. Burn history by year is provided as a binary indicator (0-1) by hexagon.
The ecological indicator metric is the percent of the landcover type that is in compliance with the recommended fire regime. The intersection of landcover data with fire history for 2006-2018 provides data for estimating the acreage burned within any time period. The sum of acres that has been burned during any year within the maximim fire return interval (i.e., marshes burned within the last 10 years) provides an estimate of acreage in compliance. Acreage in compliance in relation to acreage of the included landcovers yields the percentage in the appropriate fire return interval. Trends in compliance will be updated annually. The current target (goal) is to increase from the baseline (2018) percentage by 20% for marshes and 13% for wet prairies.
These results reflect the best available methods for determining fire history for Florida's fire-maintained habitats. As with all spatial data, a number of sources of uncertainty contribute to these estimates. The CLC is maintained on a regular basis, however changes in land cover may have occurred since maintenance. Not all land covers may be completely identified. The CLC is a raster with 10m x 10m pixel size (~ 0.0247 acres). The fire data are summarized in a 10-acre hexagon net covering the state, Results were not converted to the coarsest scale (10-acre) and so interpretation of results should be recognized as an estimate of the true acreage. And although a number of validation measures were employed to ensure the best possible identification of fire footprints in remotely-sensed images, some fires may have been missed due to cloud cover, rapid greenup, low intensity, and late in the year misattribution (Tall Timbers Final Report - unpublished). Total acreages of burning during the entire time frame may be greater than acreages in compliance, which doesn't account for multiple burns over all years.
