Grassland & Savanna Restoration (Southeast Blueprint Indicator)

Reason for Selection Native grasslands and savannas are important for many endemic species, provide critical habitat and food for pollinators, and are often hotspots for biodiversity. Once a predominant ecosystem type, grasslands and savannas have significantly declined from their historical extent. In part because of the regular disturbance (e.g., mowing, fire) typically required to maintain high-quality grasslands, they are difficult to detect through remote sensing and are not well-captured by other indicators. In addition, grassland and savanna birds are experiencing significant declines and are [currently off-track for meeting the SECAS 10% goal], so it is important that the Blueprint capture known and potential habitat. Input Data * [National Land Cover Database] (NLCD): [2021 Land Cover] * 2020 [LANDFIRE Existing Vegetation Type] (EVT) [LF 2.2.0]; [access the data] * [Grassland and savanna extent] (Southeast Blueprint indicator) - intermediary code output * Florida Natural Areas Inventory [Longleaf Sustainability Analysis v1], accessed 2-23-2024 (LSA_Restoration_Priorities_EqualWeights_v1.tif) This dataset combines equally weighted measures of longleaf pine suitability and sustainability to identify areas that are highly suitable for reestablishing longleaf pine. The suitability metric calculates the probability of suitability for longleaf restoration based on the relationship between known longleaf pine occurrences and a suite of environmental variables, such as climate, fire regime, soils, and ecosystem characteristics. The sustainability metric examines landscape connectivity, a measure called landscape integrity that evaluates overall naturalness at multiple scales, climate resilience, and ability to burn (based on proximity to buildings and urban growth projections). * U.S. Forest Service [Shortleaf pine range] (Digital Representation of Shortleaf Pine Range Map from “Atlas of United States Trees” by Elbert L. Little, Jr. and other publications), accessed 4-26-2025; [access on ArcGIvS Online] * Natural Resources Conservation Service [shortleaf pine suitability], accessed 4-14-2025 This dataset calculates overall suitability for shortleaf pine by relating shortleaf pine occurrences to multiple soil and site properties from the National Soil Information System. It considers temperature, precipitation, slope, aspect, and numerous soil characteristics such as pH, clay content, depth, drainage, and more. * [Southeast Blueprint 2025 extent] Mapping Steps * Use LANDFIRE EVT to make a layer of agricultural classes with high grassland restoration potential using the EVT Group Name field. Select pixels classified as ‘Agricultural-Fallow/Idle Cropland’, ‘Agricultural-Pasture and Hayland’, or ‘Agricultural-Wheat’. * From the Longleaf Suitability Analysis, reclassify the longleaf restoration priorities (LSA_Restoration_Priorities_EqualWeights_v1.tif) to extract the top half of the restoration classes for longleaf. * From the shortleaf pine potential layer, reclassify any areas without site limitations to 1 and assign all other areas a value of 0. Clip this layer by the shortleaf pine range. Then create a mask using 2021 NLCD landcover to include only upland forest classes (41, 42, or 43) and use it to further limit the shortleaf pine layer to only areas currently in those upland forest types. * Combine the agricultural classes with restoration potential, the top half of the longleaf restoration priorities, and the refined shortleaf pine layer into a single layer of landcover with good grassland/savanna restoration potential (referred to in the legend as “restorable landcover”). Then remove any areas that weren’t historically grassland and savanna using an intermediate input from the Blueprint grassland and savanna extent indicator (historicGrass_notMarsh.tif) that defines historic grassland and savanna areas. * From the resulting layer, use the ArcGIS Region Group function to identify patches >10 acres. * Use an intermediate output from the Blueprint grassland and savanna extent indicator (HUC12_knownOrLikely5acPlus.tif) to define grassland and savanna hubs. These are intended to elevate grassland restoration opportunities that are near other established grassland patches. Any HUC12 subwatershed that contain known or likely grassland/savanna patches >5 acres is considered a grassland hub. * To identify historic grasslands and savannas in protected areas with management potential, use an intermediate output from the grassland and savanna extent indicator (testHistoricNotCurrentGrass_selectedPAD_SECAS.tif). Use Region Group to identify patches > 10 acres. * Create a known or likely grassland/savanna layer using all classes > 4 in the grassland and savanna extent indicator. Use this to ensure all pixels in those classes are assigned a value of 1 in the final indicator. Because they are already grassland/savanna, they are a lower priority for restoration. * Create a developed areas mask from the NLCD using only the medium and high density developed classes (43 and 44), which are not easily restorable. Use the mask to make sure medium and high developed areas don’t get included in the top 4 indicator classes (highest to medium restoration priority). We do still include low density development and developed open spaces, as these less developed classes are often targets of grassland restoration. * Use conditional statements to combine all rasters together to get the final indicator values, retaining the highest value a pixel can have. * Assign the highest value to protected areas with management potential that fall within the grassland/savanna hubs. Assign a value of 6 to any undeveloped pixel within a grassland/savanna hub AND within a protected area with management potential AND within a historic grassland/savanna patch >10 acres. * Next look at other areas within the grassland/savanna hubs. Assign a value of 5 to any pixel in landcover with good restoration potential that is within a grassland/savanna hub AND within a historic grassland/savanna patch >10 acres, but NOT within a protected area with management potential. * Now look at protected areas that fall outside the grassland/savanna hubs. Assign a value of 4 to any undeveloped pixel that is within a protected area with management potential AND within a historic grassland/savanna patch >10 acres, but NOT within a grassland/savanna hub. * Next look at opportunities that are outside the grassland/savanna hubs and outside the protected areas with management potential. Assign a value of 3 to any pixel in landcover with good restoration potential that is within a historic grassland/savanna patch >10 acres, but NOT within a protected area with management potential or a grassland/savanna hub. * Assign a value of 2 to all remaining pixels of restorable grassland landcover that fall within a historic grassland/savanna patch >10 acres. * Assign a value of 1 to all known or likely current grasslands. * As a final step, clip to the spatial extent of Southeast Blueprint 2025. Note: For more details on the mapping steps, code used to create this layer is available [in the Southeast Blueprint 2025 Data Download] under > 6_Code. Final indicator values Indicator values are assigned as follows: 6 = Highest restoration priority (in a grassland/savanna hub, in a protected area with management potential, in a historic patch >10 acres) 5 = Very high restoration priority (in a grassland/savanna hub, unprotected landcover with good restoration potential, in a historic patch >10 acres) 4 = High restoration priority (outside a grassland/savanna hub, in a protected area with management potential, in a historic patch >10 acres) 3 = Medium restoration priority (outside a grassland/savanna hub, unprotected landcover with good restoration potential, in a historic patch >10 acres) 2 = Low restoration priority (other historic grassland/savanna) 1 = Very low restoration priority (already known or likely grassland/savanna) 0 = Lowest restoration priority (not identified as historic grassland/savanna) Known Issues * Savanna restoration potential is underprioritized in forests without historic longleaf or shortleaf pine. * Restoration potential is underprioritized in the Arid West region of Texas and Oklahoma. * This indicator underprioritizes some important grassland and savanna restoration opportunities on private land and in protected areas managed for multiple use. * This indicator may underestimate the extent of historic grasslands and savannas in the Kentucky portions of the Western Pennyroyal Plain. LANDFIRE predicts grassland and savanna in this area but also includes more extensive areas of wet forests with closed canopies than other sources. Much of this area is now converted to agriculture, making it more difficult to estimate historic conditions. 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 Antoine C. M., Forrest J. R. K. (2021). Nesting habitat of ground-nesting bees: a review. Ecol. Entomol. 46, 143–159. doi: 10.1111/een.12986. [[https://resjournals.onlinelibrary.wiley.com/doi/full/10.1111/een.12986]]. Dechant, J. A., M. L. Sondreal, D. H. Johnson, L. D. Igl, C. M. Goldade, M. P. Nenneman, and B. R. Euliss. 1998 (revised 2002). Effects of management practices on grassland birds: Grasshopper Sparrow. Northern Prairie Wildlife Research Center, Jamestown, ND. 28 pages. [[https://pubs.usgs.gov/unnumbered/93877/report.pdf]]. Dewitz, J., 2023, National Land Cover Database (NLCD) 2021 Products: U.S. Geological Survey data release. [[https://doi.org/10.5066/P9JZ7AO3]]. Florida Natural Areas Inventory and University of Florida Center for Landscape Conservation Planning. 2023. Longleaf Pine Sustainability Analysis Version 1 Technical Report. Tallahassee, FL. Landscape Fire and Resource Management Planning Tools (LANDFIRE), Earth Resources Observation and Science Center (EROS), U.S. Geological Survey. Published 2022-09-28. LANDFIRE 2020 Biophysical Settings (BPS) CONUS. LF 2020. Raster digital data. Sioux Falls, SD. [[https://www.landfire.gov/bps.php]]. Reid, Richard. Natural Resources Conservation Service. Shortleaf Pine Suitability. [[https://tiles.arcgis.com/tiles/SXbDpmb7xQkk44JV/arcgis/rest/services/FOR_Shortleaf_Pine_Suitability_R/MapServer?cacheKey=9ec3894970528105]]. Slater, G.L. (2004, October 7). Grasshopper Sparrow (Ammodramus savannarum): a technical conservation assessment. [Online]. USDA Forest Service, Rocky Mountain Region. Accessed February 24, 2024. [[https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5182057.pdf]]. Southeast Conservation Adaptation Strategy. 2021. Recent Trends in Southeastern Ecosystems (2021): Measuring Progress toward the SECAS Goal. [[https://secassoutheast.org/pdf/SECAS-goal-report-2021.pdf]]. U.S. Department of Agriculture, Natural Resources Conservation Service. 2010. Management considerations for grassland birds in northeastern haylands and pasturelands. Wildlife Insight. Washington, D.C. [[https://www.bobolinkproject.com/docs/NRCS_Grassland_leaflet.pdf]]. U.S. Forest Service. Shortleaf pine range. Digital Representation of Shortleaf Pine Range Map from “Atlas of United States Trees” by Elbert L. Little, Jr. and other publications. Accessed 4-26-2025. 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