Scrub is a globally and state-listed imperiled ecosystem that occurs in Florida. It is inhabited by rare, endemic, and otherwise range-restricted species of plants and animals. Evaluating patch-level metrics of habitat classes is important for determining which patches should be managed, monitored, or prioritized for land acquisition. For instance, if the objective of a conservation initiative is to conserve habitat that will support populations of a species of ground nesting bird, patches with lower perimeter-to-area ratios should be prioritized, as patches with greater perimeter-to-area ratios are often susceptible to active foraging predators. To give another example, say that a state agency plans to re-introduce a locally extirpated species of snake that relies on scrub. It may be beneficial to release individuals in patches that have low measures of isolation from each other, and have greater contiguity. In this case, patches that should be prioritized are those that have low Euclidian Nearest Neighbor distances, and high Contiguity Index values.

To demonstrate how these patch-metrics can vary across a landscape for a habitat type, I examined patches of scrub within Avon Park Airforce Range in Central Florida. I projected Cooperative Land Cover (CLC) data from FWC and FNAI to NAD 1983 UTM Zone 17 N so that the linear unit was in Meters. I clipped the projected raster to the extents of Avon Park Airforce Range, and re-classified the raster by assigning a value of 1 to Scrub, and 0 to all other habitat classes. Next, I exported the re-classified layer as a .tif file, and calculated class and patch metrics in Fragstats (Version 4.2). I calculated area, perimeter-to-area ratio, radius of gyration, shape index, contiguity, and Euclidian nearest neighbor distance. I loaded the resulting .tif file and data table containing patch-ID into ArcGIS Pro, built an attribute table for the resulting raster layer, and then joined the data table to the layer. Lastly, I symbolized the layer by each metric. Note that this procedure requires you to select the option for "Generate Patch ID File" in Fragstats.

Explanations of each of these metrics are provided here: https://fragstats.org/index.php/fragstats-metrics/patch-based-metrics.

Data Reference: Florida Fish and Wildlife Conservation Commission and Florida Natural Areas Inventory. 2023. Cooperative Land Cover version 3.7. Tallahassee, FL.