{5E591817-C13D-498A-BA0D-F3D28D986324} eng; USA utf8 dataset EnviroAtlas Coordinator U.S. Environmental Protection Agency, Office of Research and Development-Sustainable and Healthy Communities Research Program, EnviroAtlas Geospatial Data Owner (919) 541-3832 109 T.W. Alexander Drive Research Triangle Park NC 27709 EnviroAtlas@epa.gov https://www.epa.gov/enviroatlas pointOfContact 2025-07-23 ISO 19115 Geographic Information - Metadata ISO 19115:2003/Cor.1:2006(E) EnviroAtlas - Ecosystem Rarity Metrics by 12-digit HUC for the Conterminous United States 2015-05-07 publication U.S. EPA Office of Research & Development (ORD) - National Exposure Research Laboratory (NERL) Research Triangle Park NC publisher US Environmental Protection Agency (US EPA) originator This EnviroAtlas dataset identifies rare ecosystems using base landcover data from the USGS GAP Analysis Program (Version 2, 2011) combined with landscape ecology principles. The metrics included in this data set identify total rare acres and the protected rare acres within each 12-digit Hydrologic Unit (HUC). The percentage of the terrestrial area of each HUC covered by rare ecosystems as well as the percent of rare acres that are protected are also included. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets). Conservation of biodiversity remains a high priority for maintaining many ecosystem functions, and conservation efforts often focus on protecting vulnerable species. Species population measurements may not be suitable for evaluating the collective benefits and services that emerge from entire ecosystems, particularly those that do not contain rare or charismatic species. Here we combine currently available land cover data with ecosystem taxonomy and landscape ecology principles to evaluate the relative rarity of natural ecosystems in the continental US. Our goal was to develop a measure of ecosystem rarity that can distinguish ecosystems with intrinsically limited extents consistent with historic conditions (i.e. riparian or bog systems) from those that have limited area due to land conversion. We present a relative rarity metric that ranks ecosystems based on current extent, spatial pattern type, and relative uniqueness. This metric shows promise when compared to more complex and expensive methods. The majority (57%) of the area covered by 'rare' ecosystems we identify in the continental US fall within the boundaries of the Nature Conservancy's Conservation Priority Areas, whereas only 28% of our 'rare' ecosystems are currently held in protected status. The ecosystem rarity index we developed captures both fine scale species diversity as well as regional ecosystem services. This type of metric can support efforts such as creating an ecosystem Red List. The overall goal of EnviroAtlas is to employ and develop the best available science to map indicators of ecosystem services production, demand, and drivers for the nation. completed EnviroAtlas Coordinator U.S. Environmental Protection Agency, Office of Research and Development-Sustainable and Healthy Communities Research Program, EnviroAtlas Geospatial Data Owner (919) 541-3832 109 T.W. Alexander Drive Research Triangle Park NC 27709 EnviroAtlas@epa.gov https://www.epa.gov/enviroatlas pointOfContact asNeeded Ecosystem Environment theme EPA GIS Keyword Thesaurus 12-digit HUCs Biodiversity Conservation Ecology Ecosystem Ecosystem Services EnviroAtlas Environment Environmental Atlas Habitat Land Cover Management Natural Resources Protected Lands Quality Recreation Supply of Ecosystem Services theme EnviroAtlas Alabama Arizona Arkansas California Colorado Connecticut Delaware Florida Georgia Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas United States Utah Vermont Virginia Washington Washington DC West Virginia Wisconsin Wyoming place None https://edg.epa.gov/EPA_Data_License.html otherRestrictions Use Constraints: None. Please check sources, scale, accuracy, currency and other available information. Please confirm that you are using the most recent copy of both data and metadata. Acknowledgement of the EPA would be appreciated. otherRestrictions Access Constraints: None PUBLIC https://project-open-data.github.io/schema/#accessLevel Standard Technical Controls eng; USA environment -128.02839229 -65.20336449 22.7348894 51.6773602 2013-02-05 true Entity and Attribute Information Entity and Attribute Overview: Ecosystem rarity was determined through the calculation of a rarity index through the following steps: 1. The USGS GAP Analysis landcover data (Version 2, 2011) was used to identify the natural terrestrial ecosystems of the United States. This means that landcover types relating to open water and human use ( i.e. urban, agriculture, or plantation forests) were removed from the landcover data set. 2. These natural ecosystems were then grouped into their corresponding spatial pattern category, of which there are four. These four patterns are each defined by set criteria and include a discussion of disturbance regimes and are derived from the work of Comer et al. 2003. Small patch forming systems are defined as those that form small, discrete areas of vegetation cover typically limited in distribution by localized environmental features. In undisturbed conditions, typical occurrences range from 1-50 ha (2.47 - 123.5 acres). Large patch forming systems are defined as systems that form large areas of interrupted cover and typically have narrower ranges of ecological tolerances than matrix types. Individual disturbance events tend to occupy patches that can encompass a large proportion of the overall occurrence (e.g. >20%). In undisturbed conditions, typical occurrences range from 50-2,000 ha (123.5 - 4940 acres). Matrix forming systems are defined as those that form extensive and contiguous cover, occur on the most extensive landforms, and typically have wide ecological tolerances. Disturbance patches typically occupy a relatively small percentage (e.g. <5%) of the total occurrence. In undisturbed conditions, typical occurrences range in size from 2,000 to 100,000 ha (4940 - 247,000 acres). Linear systems are defined as systems that occur as linear strips and are often ecotonal between terrestrial and aquatic ecosystems. In undisturbed conditions, typical occurrences range in linear distance from 0.5 to 100 km (0.31 - 62 miles). 3. Within the four spatial pattern categories, the ecosystems were aggregated up a taxonomic level (within the National vegetation Classification (NVC) hierarchy) to the macrogroup. The NVC macrogroups are defined as subcontinental or regional communities differing by mesoclimate, geology, substrate, hydrology, and disturbance regimes (Faber-Langendoen et al. 2009). Many of the ecosystems in the GAP Version 2 dataset are similar to one another. This raised the question of whether or not the ecosystem unit was the correct scale to consider for the conservation of biodiversity. For example, there are six ecosystems with titles that begin with "Southern Coastal Plain Nonriverine Basin Swamp". Each of these six systems has a unique modifier associated, such as "Okefenokee Bay/Gum Modifier" or "Okefenokee Pine Modifier;" yet these six systems seem comparable enough to act as habitat substitutes for one another. To deal with the potential niche overlap of the individual ecosystems we aggregated up a level in the NVC hierarchy to the macrogroup level. Aggregating the ecosystems into macrogroups assures adequate variability in species assemblages, both plant and animal, between ecological communities considered in calculating the rarity metric. 4. We have first sorted the ecosystems into their corresponding spatial patterns in order to rank relative rarity amongst comparable systems. Next, we aggregated the systems within each spatial pattern type up to the macrogroup level to reduce habitat niche overlap that may exist at the finer ecosystem scale. This sorting of ecosystems by spatial pattern category followed by aggregation to the macrogroup level created a unique set of ecological entities that could not be referred to as either ecosystems or macrogroups. We refer to this unique set as ecoforms, of which there are 199. We ranked each of the four spatial pattern sets of ecoforms by descending area (i.e. the ecoform with the greatest area is ranked as 1, then the ecoform with the second greatest area is ranked as 2 etc...). We then divided this rank by the total number of ecoforms in each spatial pattern set. This ratio was then normalized by multiplying by 100 and rounding to the nearest integer. This gives us an index of rarity ranging from 0 (common) to 100 (rare). 5. A threshold value of 75 was selected; thus defining ecoforms (and corresponding ecosystems) with index values > 75 as rare. 6. The GAP Version 2 landcover raster was reclassified to a binary raster indicating whether or not a given pixel of landcover met the definition for rarity or not. 7. This binary raster was then summarized to the 12-digit HUCs using zonal statistics to give the total rare acres. 8. The rarity rankings were then compared with the Protected Areas Database of the United States (PAD-US) 1.2 to determine how much of the ecosystem area designated as rare by our analysis is currently afforded a high level of protection. PADUS 1.2 is a national database of protected lands published by the USGS GAP Analysis Program (GAP 2011b). PADUS 1.2 has categorized the level of protection for each area included within the database into four levels. Status code 1 is defined as an area with permanent protection from any resource use that results in land cover change along with a management plan designed to mimic natural disturbance regimes; this level equates with IUCN Protected area categories Ia, Ib, and II. Status code 2 is defined as an area with permanent protection and a management plan that allows selective use of resources; this level equates with IUCN Protected Area categories III, IV, V, and VI. These two highest levels of protection in the GAP protected Status (codes 1 and 2) were selected to consider the protected status of rare ecosystems. The binary raster of ecosystem rarity (output of step 6 above) was extracted using the limited PADUS 1.2 polygon data (only GAP codes 1 and 2) as a mask. The output was a raster of protected rare pixels. This raster was then summarized to the 12-digit HUCs using zonal statistics to give the total rare protected acres. If a given HUC contained no rare pixels at all, then the value for this field is null. 9. The GAP Version 2 landcover data was used to calculate the total terrestrial area of the 12-digit HUCs. The landcover raster was reclassified to remove all open water landcover types. This terrestrial-only version of the landcover was then summarized to the 12-digit HUCs using zonal statistics to give the total terrestrial area. 10. The percent of the HUC that is rare was calculated by dividing the total rare acres (output of step 7) by the total terrestrial acres (output of step 9) and multiplying by 100. There are no null values for this field. 11. The percent of the rare area protected within a HUC was calculated by dividing the total protected rare acres by the total rare acres. If a given HUC contained no rare pixels at all, then the value for this field is null. References: Comer, P., D. Faber-Langendoen, R. Evans, S. Gawler, C. Josse, G. Kittel, S. Menard, M. Pyne, M. Reid, K. Schulz, K. Snow, and J. Teague. 2003. Ecological systems of the United States: A working classification of U.S. terrestrial Systems. NatureServe, Arlington, VA. Faber-Langendoen, D., D. L. Tart, and R. H. Crawford. 2009. Contours of the revised U.S. National Vegetation Classification Standard. Bulletin of the Ecological Society of America 90:87-93. GAP, USGS. 2011a. National Landcover, Version 2. GAP, USGS. 2011b. Protected areas database of the United States (PADUS) version 1.2. Entity and Attribute Detail Citation: https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets EnviroAtlas Coordinator U.S. Environmental Protection Agency, Office of Research and Development-Sustainable and Healthy Communities Research Program, EnviroAtlas Geospatial Data Owner (919) 541-3832 109 T.W. Alexander Drive Research Triangle Park NC 27709 EnviroAtlas@epa.gov https://www.epa.gov/enviroatlas distributor https://enviroatlas.epa.gov/download/CONUS_metrics_FGDB.zip download Download The URL providing direct access to the downloadable dataset. download https://enviroatlas.epa.gov/download/CONUS_metrics_CSV.zip ESRI:ArcGIS API The endpoint of a web service to access the dataset (REST endpoint, WMS GetCapabilities URL, or a SOAP WSDL endpoint). webMapService https://www.epa.gov/enviroatlas/enviroatlas-data information Documentation URL for accessing related documents such as data dictionary, technical information about a dataset, developer documentation, etc. information https://www.epa.gov/enviroatlas information Home Page Alternative landing page used to redirect user to a contextual, Agency-hosted "homepage" for the Dataset or API information dataset Horizontal Positional Accuracy Report Data were collected using methods that have unknown accuracy (EPA National Geospatial Data Policy [NGDP] Accuracy Tier 10). For more information, please see EPA's NGDP at https://epa.gov/geospatial/policies.html Features represented have not been tested for completeness Features represented have not been tested for completeness Tests for integrity have not been performed. This lineage was generated by the FGDC CSDGM to 19139 transformation The processing steps are clearly outlined in the overview. 2013-02-05T00:00:00 unknown 2029-07-23 This metadata was automatically generated from the FGDC Content Standard for Digital Geospatial Metadata standard (version FGDC-STD-001-1998) using the 2024-02-09T11:11:00 version of the FGDC CSDGM to ISO 19139 transform. EnviroAtlas Coordinator U.S. Environmental Protection Agency, Office of Research and Development-Sustainable and Healthy Communities Research Program, EnviroAtlas Geospatial Data Owner (919) 541-3832 109 T.W. Alexander Drive Research Triangle Park NC 27709 EnviroAtlas@epa.gov https://www.epa.gov/enviroatlas pointOfContact