These data show the Fire History Indicator for the Pine Flatwoods and Dry Prairie Conservation Asset in Florida.
Fire Regime is an ecological indicator for the Pine Flatwoods and Dry Prairie Conservation Asset of the Florida Landscape Conservation Project (LCP). 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. A suite of ecological indicators, carefully selected to represent important characteristics of each CA, also inform decision-making efforts. Indicators also offer metrics that serve to guide conservation activities, with clear measures of both needs and management effectiveness and provides a means to evaluate current status and monitor trends. Indicator 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 Pine Flatwoods and Dry Prairie in its natural state. Prior to human habitation, wildfires were common in Florida landscapes from natural sources, such as lightning. Fires contributed to the composition and structure of a number of Florida's habitats and many native animals depend on these fire-maintained conditions. Conditions vary with fire frequency, with more frequent fires reducing tree and understory cover and increasing herbaceous cover. Some plant species are dependent on fire for blooming and seed production. Bird communities are varied, depending on the composition and structure of the plants. Some birds are more common in tree canopies (i.e., Pine Warblers, Brown-headed Nuthatches, etc.) whereas others may be attracted to understory and shrubs for nesting and foraging. In dry prairies, the endangered grasshopper sparrow depends on grassy expanses maintained through fire, among other factors. Lack of fire can also lead to a fuel build-up that promotes uncontrollable wildfires that can endanger humans and may not achieve the benefits of a controlled burn. With the Conservation Asset, landcovers are grouped into three fire-regime categories: flatwoods (including Dry, Mesic, and Scrubby Flatwoods) - 1-4 years; dry prairie - 1-3 years; and Pine Rocklands - 3-7 years.
Fire management may be difficult to implement, however, for both financial and societal reasons. Controlled burns require significant financing and 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, however, 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,
Land covers 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 Pine Flatwoods and Dry Prairie..
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.), standardized 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 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., flatwoods burned within the last 4 years) provides an estimate of acreage in compliance. Percentages are then calculated against the total acreage of the landcover(s) in the CLC. Trends will be compared to the target, or goal, of 36% for flatwoods, 49% for dry prairies, and 27% for pine rocklands.
These results reflect the best available methods for determining fire history for Florida's fire-maintained habitats. A number of sources of uncertainly contribute to all estimates and considered in interpretation. Landcovers may change more rapidly than updates and may be imperfectly identified. The CLC represents a uniquely fine-scale landcover data for both classification levels and resolution (10m x 10m or ~ 0.0247 acres), but represents a summary within the cell. Likewise, fire history is summarized within 10-acre hexagons and fire footprints may be missed for a variety of reasons (image cloud cover, rapid greenup, low intensity fires, etc.). Despite caveats, the fire database represents a leap forward in fire history that managers and others have desired for many years and provides much needed information for conservation professionals in Florida.
