Species Data Download

<< Back to Species Data Overview

Species and Ancillary Data – Downloads and Information

1. Download species range and predicted habitat data >>
2. Download ancillary data >> (land cover, forest edge, human impact, etc.)
3. Download additional data >> (slope, aspect, canopy cover, etc.)
4. Browse data notes >> for all data types

Ancillary Data

Below is a list of the ancillary data available for download. See the Info section below for more information on each ancillary dataset. Ancillary data is delivered as zipped ArcGIS Grids. Note: Data are divided up by species modeling regions and you will need 7zip to decompress the files.

• Modeling Regions: The lower 48 states of the U.S. were divided into six regions for modeling purposes. Each of the ancillary data layers are split into these six regions and models were run within a region and regional model output were compiled to create a complete distribution model across a species range. The regions are based on grouped MRLC zones. Download the national boundaries data. Download the regional boundaries data.
• Human Impact Avoidance: Regional layers indicating how intolerant a species is to human disturbance. Download human impact avoidance data. (description)
• Elevation: Regional Digital Elevation Models (DEM). Download elevation data file.  (description)
• Land Cover: Regional GAP National Land Cover Data. Download land cover data file.  (description)
• Forest Edge: Regional ecotone (i.e., edge) between forested and non-forested environments taken from the GAP land cover data. Download forest edge data. (description)
• Forest/Open Ecotone + Woodlands/Shrublands: National layer of ecotone (i.e., edge) between forested and non-forested environment. Download forest and ecotone habitats data. (description)
• Hydrography: National data from the USGS National Hydrography Dataset (NHD) used in modelling. Download hydrography data. (description)

To obtain all ancillary data for the entire U.S. :

• Part 1: Landcover, Elevation, Human Impact Avoidance, Forest Edge and Forest/Open Ecotone + Woodlands/Shrublands Click here to download. File size: 5 GB.
• Part 2: Hydrography Click here to download. File size: 16 GB.

Additional Data

In addition to GAP’s ancillary datasets that are used in species model, there are additional GAP national datasets available. These include slope, aspect, and percent canopy cover.

• Slope: Nationwide coverage of slope, which represents the percent of change of elevation for each 30 m cell. It is based on DEM data. Download slope data file.
• Aspect: Nationwide coverage of aspect, which describes the direction of slope in degrees. It identifies the downslope direction of maximum change from each raster cell to its neighbors. Download aspect data file.
• Percent canopy cover: Nationwide cover of percent canopy cover. It was derived from the National Land Cover Dataset (NLCD). This dataset is a continuous canopy cover percentage. Download percent canopy cover data.

Data Notes

The GAP ancillary datasets available for download are described below including descriptions of data variables and their values as well as the connection with model reports. The descriptions reflect how the data were used in the species models. For a clearer description of the data itself, refer to the metadata supplied for each layer. Prior to downloading ancillary data, please read the data descriptions below to ensure they will meet your data needs.

• Human impact avoidance: Environments dominated by human disturbance such as roads, cities, and the constructed materials that support human habitation have profound effects on species. For most species, this data layer was used to exclude species from a portion of the landscape. However, some species respond favorably to human habitats, therefore this data layer was used in an inclusionary manner.

  Model Report: If a species’ model uses the model variable for human impact avoidance, then downloading these ancillary data will provide the level of avoidance described below:

  ♦ High – For species that are very intolerant of human disturbance. All portions of the landscape identified as being directly influenced by human disturbance are eliminated from the predicted distribution.
  
  ♦ Medium – For species that are moderately intolerant of human disturbance. Only portions of the landscape identified as being highly or moderately influenced by human disturbance are eliminated from the predicted distribution.
  
  ♦ Low – For species that are partially intolerant of human disturbance. Only portions of the landscape identified as being highly influenced by human disturbance are eliminated from the predicted distribution.

• Elevation: Some species respond to environments directly related to altitudinal variation. Elevation (e.g., DEM) is easily implemented in spatial modeling by limiting the model to the minimum and maximum values explicitly stated in the literature. DEMs are utilized directly and are measured in meters above mean sea level.

  Model Report: If a species’ model uses elevation as a model variable, then download the ancillary data for elevation.

• Hydrographic information: Water and its location on the landscape is a very important aspect of species habitats. The source for hydrographic data was the USGS National Hydrography Dataset (NHD).
  
  
  
  Model Report: If a species’ model report uses any of the hydrographic information, see the hydrography data for information with regards to salinity, water type, and velocity.
  
  
  
  Types of water:
  
  ♦ Flowing Water – Flowing water represents hydrographic features such as streams, rivers, springs, seeps, ditches with moving water, etc.
  
  ♦ Standing Water – Standing water represents hydrographic features such as lakes, ponds, reservoirs, bays, inlets, estuaries, ocean, ditches with stagnant water, etc.
  
  ♦ Wet Vegetation – Wet vegetation represents hydrographic features such as swamps, marshes, Carolina bays, etc. This includes a collection of map units representing seasonally or tidally inundated woody and non-woody plants.
  
  
  
  Salinity: Water salinity is a major factor when considering habitat conditions for many species. However, the dynamic and complex nature of water systems makes the development of a highly refined and reliable data layer challenging. Therefore, we developed three general categories to include in species habitat models for species requiring water.
  
  ♦ Freshwater Only
  
  ♦ Brackish/Salt Water Only
  
  ♦ All Water (i.e., both brackish/salt water and freshwater)
  
  
  
  Stream velocity: For some aquatic species, this is an important aspect of their habitat, such as oxygenation levels, presence of invertebrate prey, and amount of sediment within the water column and on streambed substrates. Stream velocity (i.e., stream gradient) was derived from a combination of streams and slopes calculated from a digital elevation model (DEM), which created three categories for stream gradient.
  
  ♦ Slow Only – For species that require slow moving or almost stagnant sections of streams or rivers. Typically these are areas where the underlying topography is flat (0 % gradient).
  
  ♦ Fast Only – For species that require high velocity sections of streams or rivers. Typically these are areas where the underlying topography is steep. A threshold of > 5 % gradient was used.
  
  ♦ All Types – For species that can utilize either fast or slow sections of streams or rivers.
  
  
  
  Distance into and from type of water:
  
  ♦ Distances from a type of water were: >4000, 4000, 2000, 1000, 500, 250, 120, 60, 30, and 0 meters
  
  ♦ Distances into a type of water were: 0, 30, 60, 120, 250, 500, 1000, 2000, 4000, and >4000 meters

• Land cover information
  
  
  
  Land Cover: The ecological systems mapped in the GAP National Land Cover Data were used as ‘map units’ to describe habitat types preferred by species.
  
  
  
  Model report: If a species’ model uses map units as a model variable, then download the ancillary data for land cover. Map units are designated as either primary or secondary. Primary maps units are defined as those ecological systems critical for a species’ reproduction and survival. Secondary map units are those ecological systems generally not critical for reproduction and survival, but typically are used in conjunction with primary map units for foraging, roosting, and/or sub-optimal nesting locations. Secondary map units are selected only when located within a specified distance from primary map units.
  
  
  
  Patch Size: The type and size of clusters of habitat can be assessed with spatial modeling. We used patch size to indicate minimum amounts of contiguous habitat needed for a species. This variable requires the generation of cluster sizes in the actual modeling code during post processing. In other words, these model variables are not independent ancillary data layers.

  Model report: If a species’ model uses patch size, this variable is generated in the actual modeling code during post processing. Any cells that do not form a minimum contiguous patch* are eliminated. There are no specific ancillary layers for this variable.

  *Contiguous Patch – Minimum size (ha) – This parameter is set using the most conservation values explicitly stated in the species literature.

• Forest and Ecotone Habitats: The ecotone (i.e., edge) between forested and non-forested environments can be a critical aspect of habitat. We grouped map units into forested, non-forested, and shrubland/woodland land cover types to create unique data layers. These data layers can then be buffered at specified distances to identify species habitats. Aggregated map units can be compared and contrasted to identify areas of transition between these broad categories. They can also be used to identify core areas or contiguous blocks of similar type (i.e., interior) through buffering.
  
  
  
  ♦ Forested map units included deciduous forest, evergreen forest, mixed forest, palustrine forested wetland, and estuarine forested wetland.
  
  ♦ Non-forested map units were defined as water, pasture/hay, agricultural areas, urban/developed, marshes, beaches, etc.
  
  ♦ Woodland/shrubland map units were defined as those ecological systems and land uses containing a majority of short, scrubby, woody vegetation or sparsely canopied treed vegetation.
  
  
  
  Ecotone type and width:
  
  ♦ Ecotone type: 
  
  Forest/Open Ecotone Only – This data layer represents the transitional areas between forest and open, non-forested habitats.
  
  
  
  Model report: If a species’ model uses edge type and it is set as Forest/Open Ecotone + Woodlands/Shrublands, then download the ancillary data for forest edge and forest/open ecotone + woodlands/shrublands.
  
  
  
  ♦ Ecotone Width: This distance represents a symmetrically buffered edge (i.e., 0, 30, 60, 120, 250, 500, and 1000 meters). For example, an ecotone width of 500 meters includes 250 meters into forest and 250 meters into open.
  
  
  
  Buffer distances:
  
  --Distances into ecotone (e.g., forest edge): 0, 30, 60, 120, 250, 500, 1000, 2000, 4000, and >4000 meters
  
  --Distances away ecotone (e.g., forest edge: >4000, 4000, 2000, 1000, 500, 250, 120, 60, 30 and 0 meters
  
  
  
  Model report: If a species’ model uses ecotone width, this variable is applied to the corresponding ecotone(s) described above (see Ecotone type).

  ♦ Forest Interior and width: This data layer is comprised of unique aggregations of forest and non-forest map units taken from the GAP land cover data. See above under Forest and Ecotone Habitats for descriptions of the forest and non-forest map units.

  Model report: If a species’ model uses forest interior as a model variable, then download the ancillary data for forest edge.

  For a species that requires interior forest (e.g., uses):
  
  --Distances into forest from forest edge: 0, 30, 60, 120, 250, 500, 1000, 2000, 4000, and >4000 meters
  
  --For a species that avoids interior forest (e.g., avoids)
  
  --Distances away from forest from forest edge: >4000, 4000, 2000, 1000, 500, 250, 120, 60, 30, and 0 meters