Caribbean Habitat Patch Size (Small Islands) (Southeast Blueprint Indicator)

Large areas of intact natural habitat are favorable for conservation of numerous species, including reptiles and amphibians, birds, and large mammals. Historically, many Caribbean islands, especially smaller ones, experienced dramatic habitat alteration across much of their land mass from intensive colonial agriculture (such as sugar cane cultivation) and later by urbanization and other anthropogenic modifications (Fitzpatrick et al. 2007, CEPF 2023). As a result, contiguous natural habitat patches are particularly important for supporting native species, restoring native vegetation, and maintaining ecosystem services. This indicator roughly follows the same approach for evaluating patch size used by the intact habitat cores indicator in the continental part of the Southeast Blueprint (Esri 2017), but lowers the highest patch size threshold, recognizing that the maximum patch size on small Caribbean islands is lower than in the continental Southeast and on large islands. Input Data * [Southeast Blueprint 2023 subregions]: Caribbean * [Caribbean island extent and size] * [Southeast Blueprint 2023 extent] * 2020 [LANDFIRE Existing Vegetation Type] (EVT) and [Operational Roads (Roads)] (v2.2.0) for Puerto Rico and the U.S. Virgin Islands; [access the data for U.S. Insular Areas] Mapping Steps * Reclassify the LANDFIRE EVT data into natural and unnatural classes. All classes in “EVT_NAME” that start with “Quarries”, “Developed”, or “Agriculture” are considered unnatural. “Caribbean bush fruit and berries”, which captures sun coffee plantations, is also considered unnatural, while “tropical agroforestry plantation”, which captures shade coffee, is considered natural. Water is classified as “natural”. * Reclassify the Caribbean island extent layer to assign all islands a value of 1 and assign the ocean a value of NoData. * Multiply the reclassified LANDFIRE natural/unnatural layer and island extent data. This makes the ocean NoData, but retains freshwater, smaller salt ponds, and enclosed brackish water areas, as well as terrestrial areas on the islands. * Reclassify primary, secondary, and tertiary roads in the LANDFIRE roads layer as barriers. * Combine the natural/unnatural raster and roads raster to identify natural areas without roads. * Use region group to find the size of patch that each pixel belongs to. * Reclassify based on the final indicator values seen below. * Make a small island mask using the island extent layer for “small” and “medium” islands. Use this mask to include only habitat patches within that mask, excluding large islands, which are captured in a different indicator. * Clip to the Caribbean Blueprint 2023 subregion. * As a final step, clip to the spatial extent of Southeast Blueprint 2023. Note: For more details on the mapping steps, code used to create this layer is available [in the Southeast Blueprint 2025 Data Download] or [Caribbean-only Southeast Blueprint 2025 Data Download] under > 6_Code. Final indicator values Indicator values are assigned as follows: 4 = Large patch (>1,000 acres) 3 = Medium patch (>100-1,000 acres) 2 = Small patch (>10-100 acres) 1 = Very small patch (≤10 acres) 0 = Developed or agriculture Known Issues * Some small dirt roads serve as hard boundaries for habitat cores. While this makes sense for some species, this indicator likely underestimates the effective size of the patch for some more mobile animals. * This indicator doesn’t account for variation in habitat condition within the patch. * In Eastern St. Croix, where it’s particularly dry, this indicator can underestimate or overestimate patch size. LANDFIRE has trouble differentiating pasture from natural thornscrub in this area. Pasture isn’t considered natural in this indicator, so any areas of thornscrub misclassified as pasture would underestimate patch size, while areas of pasture classified as thornscrub would overestimate patch size. * Some docks are overprioritized due landcover misclassification. LANDFIRE sometimes misclassifies docks as forests, so they can get included in habitat patches for this indicator. Disclaimer: Comparing with Older Indicator Versions There are numerous problems with using Southeast Blueprint indicators for change analysis. Please consult Blueprint staff if you would like to do this (email [hilary_morris@fws.gov]). Literature Cited Critical Ecosystem Partnership Fund (CEPF). 2023. Caribbean Islands – Threats. [[https://www.cepf.net/our-work/biodiversity-hotspots/caribbean-islands/threats]]. Esri Green Infrastructure Center, Inc. 2017. Esri Green Infrastructure Data Description. [[https://www.arcgis.com/sharing/rest/content/items/5561da06127d48a982d6b91929f29666/data]]. Fitzpatrick, Scott & Keegan, William. (2007). Human Impacts and Adaptations in the Caribbean Islands: an Historical Ecology Approach. Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 98. 29 - 45. 10.1017/S1755691007000096. [[https://www.cambridge.org/core/journals/earth-and-environmental-science-transactions-of-royal-society-of-edinburgh/article/abs/human-impacts-and-adaptations-in-the-caribbean-islands-an-historical-ecology-approach/68BFF9386CA9BDAD3FB44E5C937AC92F]]. LANDFIRE, Earth Resources Observation and Science Center (EROS), U.S. Geological Survey. Published August 1, 2022. LANDFIRE 2020 Existing Vegetation Type (EVT) Puerto Rico US Virgin Islands. LF 2020, raster digital data. Sioux Falls, SD. [[https://www.landfire.gov]]. LANDFIRE, Earth Resources Observation and Science Center (EROS), U.S. Geological Survey. Published August 1, 2022. LANDFIRE 2020 Operational Roads Puerto Rico US Virgin Islands. LF 2020, raster digital data. Sioux Falls, SD. [[https://www.landfire.gov]].