Data Set Citation:
When using this data, please cite the data package:
NCEAS 12069: Cavender-Bares: Linking phylogenetic history, plant traits, and ecological processes at multiple scales , National Center for Ecological Analysis and Synthesis , and Reeves R. 2008.
USA Bailey's Ecoregions polygon map and R script for grid sampling
nceas.935.3 (http://knb.ecoinformatics.org/knb/metacat/nceas.935.3/nceas)
General Information:
Title:USA Bailey's Ecoregions polygon map and R script for grid sampling
Identifier:nceas.935
Abstract:
This package consists of a geo-spatial data file, specifically, an ESRI polygon shape file, containing approximately 1700 polygons depicting the Bailey's Eco Regions classification system. (Consult http://www.nationalatlas.gov/mld/ecoregp.html for a summary of this system). Also included is an R-language script that applies a regularly-spaced point grid on top of the polygon map, and produces a geospatial point file containing samples of the Bailey's region code at each point in the grid.
Keywords:None:
  • Baileys Ecoregions (theme)
  • Ecoregions (theme)
  • geospatial (theme)
  • United States landcover (place)
Publication Date:2008-07-22
Data Table, Image, and Other Data Details:
Metadata download: Ecological Metadata Language (EML) File
Data Table:ZIP Archive: Baileys Ecoregion Polygons and R grid sampling script ( View Metadata | Download File download)

Involved Parties

Data Set Creators:
Organization:NCEAS 12069: Cavender-Bares: Linking phylogenetic history, plant traits, and ecological processes at multiple scales
Organization:National Center for Ecological Analysis and Synthesis
Individual: Rick Reeves
Organization:National Center for Ecological Analysis and Synthesis
Address:
735 State Street,
Santa Barbara, California 93105 USA
Phone:
805 892 2533 (voice)
Email Address:
reeves@nceas.ucsb.edu
Data Set Contacts:
Individual: Rick Reeves
Organization:National Center for Ecological Analysis and Synthesis
Address:
735 State Street,
Santa Barbara, California 93105 USA
Phone:
805 892 2533 (voice)
Email Address:
reeves@nceas.ucsb.edu
Associated Parties:
Individual: Jeremy Lichtstein
Metadata Providers:
Individual: Rick Reeves

Data Set Characteristics

Geographic Region:
Geographic Description:Continental United States
Bounding Coordinates:
West:  -127.9167  degrees
East:  -65.4167  degrees
North:  51.5000  degrees
South:  22.9167  degrees
Time Period:
Begin:
1994-01-07
End:
2004

Sampling, Processing and Quality Control Methods

Step by Step Procedures
Step 1:  
Description:

Obtaining Bailey's Ecoregions polygons

First, I obtained the polygon shape file from the following web site: http://www.nationalatlas.gov/atlasftp.html#ecoregp For more information about Ecoregions, consult the USDA Forest Service site: http://www.fs.fed.us/rm/analytics/publications/ecoregionsindex.html Next, I developed an R script that imposes a regularly-spaced point grid (at user-specified resolution) on top of the polygon map, and then extracts the ECOCODE polygon attribute for he polygon directly underneath each point in the grid. Next, I developed an R script To generate the final data set, I employed the sampling method described in the Sampling Description, below.
Sampling Area And Frequency:
Dataset covers the continental United States.
Sampling Description:
We used an R script to impose a regular, rectangular sampling grid on top of the polygons, and extract the ecoregion type found at each point. ESRI point Shape File. Within the R script, the spatial sampling parameters (sampling interval in degrees Latitude and Longitude) are variables that can be set by the user, enabling creation of point grids with different spatial resolution. By executing the program using different resolution parameters, the user generates 'sampled point files' in Shape File format at different spatial resolutions.

Data Set Usage Rights

no restrictions
Access Control:
Auth System:knb
Order:denyFirst
Metadata download: Ecological Metadata Language (EML) File