Intact Habitat Cores (2023)

This layer was created as part of Esri’s Green Infrastructure Initiative and can be used for Green Infrastructure (GI) planning at national, regional, and more local scales. Additional companion data pertaining to habitat fragments and landscape connectivity, including a Habitat Cost Surface, Habitat Connectors, and Intact Habitat Cores by Betweenness are also envisioned to be published in late 2023. This layer represents modeled Intact Habitat Cores, or minimally disturbed natural areas at least 100 acres in size and greater than 200 meters wide. Esri created these data following a methodology outlined by the Green Infrastructure Center Inc. These data were generated using 2019 National Land Cover Data. Cores were derived from all “natural” land cover classes and excluded all “developed” and “agricultural” classes including crop, hay and pasture lands. The resulting cores were tested for size and width requirements (at least 100 acres in size and greater than 200 meters wide) and then converted into unique polygons. This process resulted in the generation of over 500,000 cores. Cores were then overlaid with a diverse assortment of physiographic, biologic and hydrographic layers to populate each core with attributes (63 in total) related to the landscape characteristics found within. A detailed data and methods description can be found below and here: Detailed methodology for Intact Habitat Cores data creation. See this tile layer for a version that enables rapid visualization. The previous 2017 version can be found here for map packages and here for a map service. This layer utilized updated data inputs from the previous version, they include: New enrichment variables added: Areas of Unprotected Biodiversity Importance (NatureServe) Map of Biodiversity Importance (NatureServe) Updated data layers for cores geometry and enrichment: National Land Cover Database (2019) National Hydrology Dataset Plus Version 2.1 (2019) National Wetlands Inventory (2022) TIGER Paved Roads (2021) TIGER Railroads (2021) Protected Areas Database of the United States (PAD-US) Levels 1 – 4 (2022) All source data used to derive this layer and cores attribution is as follows: Areas of Unprotected Biodiversity Importance of Imperiled Species in the United States NatureServe Network. April 2021. The Map of Biodiversity Importance. Arlington, VA. U.S.A. NatureServe. Biodiversity Priority Index Areas: Endemic species, small home range size and low protection status Jenkins, C. N., Houtan, K. S. van, Pimm, S. L., & Sexton, J. O. (2015). US protected lands mismatch biodiversity priorities. Proceedings of the National Academy of Sciences , 112(16), 5081–5086. https://doi.org/10.1073/pnas.1418034112 Ecological Land Units (Sayre, R., J. Dangermond, C. Frye, R. Vaughan, P. Aniello, S. Breyer, D. Cribbs, D. Hopkins, R. Nauman, W. Derrenbacher, D. Wright, C. Brown, C. Convis, J. Smith, L. Benson, D. Paco VanSistine, H. Warner, J. Cress, J. Danielson, S. Hamann, T. Cecere, A. Reddy, D. Burton, A. Grosse, D. True, M. Metzger, J. Hartmann, N. Moosdorf, H. Dürr, M. Paganini, P. DeFourny, O. Arino, S. Maynard, M. Anderson, and P. Comer, 2014, A New Map of Global Ecological Land Units — An Ecophysiographic Stratification Approach. Washington, DC: Association of American Geographers. 46 pages https://www.aag.org/wp-content/uploads/2021/12/AAG_Global_Ecosyst_bklt72.pdf Ecologically Relevant Landforms Theobald DM, Harrison-Atlas D, Monahan WB, Albano CM, 2015, Ecologically-Relevant Maps of Landforms and Physiographic Diversity for Climate Adaptation Planning. PLOS ONE 10(12): e0143619 . https://doi.org/10.1371/journal.pone.0143619 GAP Level 3 Ecological System Boundaries U.S. Geological Survey (USGS) Gap Analysis Project (GAP), 2022, GAP/LANDFIRE National Terrestrial Ecosystems 2011: U.S. Geological Survey data release, https://doi.org/10.5066/P9Q9LQ4B . gSSURGO Soil Survey Staff. Gridded Soil Survey Geographic (gSSURGO), 2022, Database for the Conterminous United States. United States Department of Agriculture, Natural Resources Conservation Service , https://gdg.sc.egov.usda.gov/ . Human Modified Theobald, D.M., 2013, A general model to quantify ecological integrity for landscape assessments and US application. Landscape Ecol 28, 1859–1874. https://doi.org/10.1007/s10980-013-9941-6 LCC Network Areas Landscape Conservation Cooperatives, 2015, Landscape Conservation Cooperatives, USA. Available online at https://www.sciencebase.gov/catalog/item/55b943ade4b09a3b01b65d78 Local Landforms Karagulle, D, Frye, C, Sayre, R, et al. Modeling global Hammond landform regions from 250-m elevation data. Transactions in GIS . 2017; 21: 1040– 1060. https://doi.org/10.1111/tgis.12265 *Scaled the neighborhood windows from the 250-meter method described in the paper, and then applied that to 30-meter data in the U.S. Map of Biodiversity Importance – Species Richness NatureServe Network. April 2021. The Map of Biodiversity Importance. Arlington, VA. U.S.A. NatureServe. National Elevation Dataset (NED) Gesch, D. B., Evans, G. A., Oimoen, M. J., Arundel, S., & Sensing, A. S. for P. and R. (2018). The National Elevation Dataset (pp. 83–110). American Society for Photogrammetry and Remote Sensing. //pubs.er.usgs.gov/publication/70201572 NHDPlus Version 2.1 Environmental Protection Agency and U.S. Geological Survey, 2019, National Hydrology Dataset Plus (Ver. 2.1. December 2019). Available online at https://www.epa.gov/waterdata/nhdplus-national-hydrography-dataset-plus NLCD – National Land Cover Database (2019) Dewitz, J., and U.S. Geological Survey, 2021, National Land Cover Database (NLCD) 2019 Products (ver. 2.0, June 2021): U.S. Geological Survey data release. https://doi.org/10.5066/P9KZCM54 NOAA C-CAP Coastal Change Analysis Program Regional Land Cover and Change (2016) National Oceanic and Atmospheric Administration, Office for Coastal Management, 2016, Coastal Change Analysis Program Regional (C-CAP) Regional Land Cover. Charleston, SC: NOAA Office for Coastal Management. Available online at www.coast.noaa.gov/htdata/raster1/landcover/bulkdownload/30m_lc/ . Number of Endemic Species Jenkins, C. N., van Houtan, K. S., Pimm, S. L., & Sexton, J. O. ,2015, US protected lands mismatch biodiversity priorities. Proceedings of the National Academy of Sciences , 112(16), 5081–5086. https://doi.org/10.1073/pnas.1418034112 NWI – National Wetlands Inventory (2022) U.S. Fish & Wildlife Service, 2022, National Wetlands Inventory. U.S. Fish & Wildlife Service. Available online at https://data.nal.usda.gov/dataset/national-wetlands-inventory . PAD-US Protected Areas Database U.S. Geological Survey (USGS) Gap Analysis Project (GAP), 2022, Protected Areas Database of the United States (PAD-US) 3.0: U.S. Geological Survey data release, https://doi.org/10.5066/P9Q9LQ4B . SSURGO (2021) Soil Survey Staff, 2021, Natural Resources Conservation Service, United States Department of Agriculture. Web Soil Survey. Available online at //websoilsurvey.nrcs.usda.gov/. TIGER Paved Roads (2021) Geography Division, 2021, TIGER/Line Shapefiles, U.S. Census Bureau. Available online at https://www.census.gov/cgi-bin/geo/shapefiles/index.php?year=2021&layergroup=Roads TIGER Rails (2021) Geography Division, 2021, TIGER/Line Shapefiles, U.S. Census Bureau. Available online at https://www.census.gov/cgi-bin/geo/shapefiles/index.php?year=2021&layergroup=Rails TNC Terrestrial Ecoregions (Updated 2021) The Nature Conservancy, 2021, Terrestrial Ecoregions, The Nature Conservancy. Available online at https://geospatial.tnc.org/datasets/b1636d640ede4d6ca8f5e369f2dc368b/about Unique Ecological Systems Based upon work by Aycrigg, Jocelyn L, et. al. (2013) Representation of Ecological Systems within the Protected Areas Network of the Continental United States. PLos One 8(1):e54689. *New data constructed by Esri staff, using TNC Ecological Regions as summary areas. Other Reference Materials: Attribute table crosswalk between 2017 and 2023 Intact Habitat Cores layers Detailed methodology for Intact Habitat Cores data creation Data Coordinate System: WGS 1984 Web Mercator Evaluation: Scripts for constructing local cores and scoring them using the Green Infrastructure Center’s methodology are available at Esri's Green Infrastructure site. The creation of a national core quality index is a very ambitious objective, given the extreme variability in ecosystem conditions across the United States. The additional attributes were intended to provide flexibility in accommodating regional or local environmental differences across the U.S. Two general approaches were used in the developing core quality index values. The first (default) follows the guidance of the Green Infrastructure Center’s scoring approach developed for the southeastern US where size of the core is the primary determinant of quality. The second; Bio-Weights puts more emphasis on biodiversity and uniqueness of ecosystem type and de-emphasizes slightly the importance of core size. This is to compensate for the very large intact core habitat areas in the west and southwest which also have comparatively low biodiversity values. Scoring values: Default Weights: 0.4, # Acres 0.1, # Thickness 0.05, # Topographic Diversity (Standard Deviation) 0.1, # Biodiversity Priority Index (Species Richness in GIC original version) 0.05, # Percentage Wetland Cover 0.03, # Ecological Land Unit – Shannon-Weaver Index (Soil Variety in GIC original version) 0.02, # Compactness Ratio (Area relative to the area of a circle with the same perimeter length) 0.1, # Stream Density (Linear Feet/Acre) 0.05, # Ecological System Redundancy (Rare/Threatened/Endangered Species Abundance (Number of occurrences) in GIC original version) 0.1, # Endemic Species Max (Rare/Threatened/Endangered Species Abundance (Number of unique species in a core) in GIC original version) Bio-Weights: 0.2, # Acres 0.1, # Thickness 0.05, # Topographic Diversity (Standard Deviation) 0.25, # Biodiversity Priority Index (Species Richness in GIC original version) 0.05, # Percentage Wetland Cover 0.03, # Ecological Land Unit – Shannon-Weaver Index (Soil Variety in GIC original version) 0.02, # Compactness Ratio (Area Relative To The Area Of A Circle With The Same Perimeter Length) 0.1, # Stream Density (Linear Feet/Acre) 0.1, # Ecological System Redundancy (Rare/Threatened/Endangered Species Abundance (Number of occurrences) in GIC original version) 0.1, # Endemic Species Max (Rare/Threatened/Endangered Species Diversity (Number of unique species in a core) in GIC original version)