Sampling efforts were stratified within pre-determined mapping areas that represented modified Bailey's (1994) ecoregions. Training sites were selected opportunistically while traversing all navigable roads in a mapping zone and identifying areas where the appropriate size (1-hectare minimum area) and composition (stand homogeneity) requirements were met. The data collected at each site involved ocular estimates of biotic and abiotic landcover components, including percent cover of dominant plant species and physical data such as elevation, slope, aspect, and landform. Each sample location was assigned an appropriate landcover label based on the Ecological System concept developed by NatureServe (2004) for natural and semi-natural terrestrial vegetation. The scientific naming convention used for plant species identification was the Natural Resources Conservation Service (NRCS) On-Line Plants Database, current as of April 2005.
Site Identification includes a final letter indicating that field observers made a series of consecutive observations that had the same plant species and cover observations. Sites that have this final letter are type "R" sites. Plant Species and cover data from these sites were updated from source sites. Cover data provided in the Arizona Field database includes only 2D cover by site. Site "R" data was updated were needed from source sites. Cover data estimates were made by both a class cover range and by percentage. Not all sites contain cover data.
Additional tables were also compiled to provide descriptive information about some of the fields like Landform, Ecological Systems entries, Physiognomic Classes, and Hydrologic Classes. A Plant list of all species found at the training site was also compiled. There are also photos linked to the database available for download.
Site Identification = A unique site identifier formatted by a combination of a 2-letter state code pointing to the location of the team collecting the field data, a 6-digit number derived from the date of the observation (MMDDYY), a 2-digit or letter identifier of the field team collecting the observations, a 3-digit number indicating that site number for that day, and for some sites an alphabetical letter. The final letter indicates that field observers made a series of consecutive observations that had the same plant species and cover observations. Sites that have this final letter are type "R" sites. (For Example: AZ01030202001 or AZ01040202002A).
State = 2-letter code for true geographic location of state for site.
Map Zone = A 4-letter code of the geographic location by map zone of the site (For Example: HUAL = Hualapai).
Mega Map Zone = 2-letter and 1-digit indicator of the geographic location by mega map zone of the site representing a composite of one or map zones (For Example: AZ-2)
Plot Size = Estimation by field observers of the size of the vegetation type at the site. Values include: 2 ha, 2-5 ha, 5-10 ha, 10-25 ha, >25 ha. Otherwise the site is assumed to be no larger than 2 ha.
Datum = Datum of the UTM projection for the site.
UTM Zone = Number of the UTM zone of the site.
Easting = A 6-digit number for the UTM easting of the site.
Northing = A 7-digit number for the UTM northing of the site.
Photos = Number of photos taken at a site. Not all sites have photos.
Confidence = Index constructed from a composite of the observation team of their assignment of an Ecological system either Ecosystem or Alliance. See table (tbl_confid_list_az) for more information about the class assignments.
Ecological System = Assignment of an ecological system for a site based on definitions and descriptions provided by Nature Serve. Through the course of obtaining field data definitions changed for final ecological system assignment for a site if the vegetation data pointed to another system. Field teams switched from alliance to ecological system assignment during the course of collecting field data throughout the state. Not all sites have an ecological system were possible models were later used to assign an ecological systems based on alliance designation and site location. See table (tbl_nlcd_list_az) for a list of ecological systems found at sites. Clicking the down arrow displays a brief description of the ecological system.
NVCS Alliance = Assignment of a vegetation type for a site based on definitions and descriptions provided by Nature Serve. If no alliance descriptor was available, alliance designations were derived from alliance nomenclature. Through the course of obtaining field data definitions changed for final alliance assignment for a site if the vegetation data pointed to another designation. See table (tbl_alliance_list_az) for a list of alliances found at sites.
Physiognomic Class = Physiognomic class as defined in TNC's Terrestrial Vegetation Classification System. List of entries and descriptions provided in table (tbl_physio_list_gap). Clicking the down arrow displays a brief description of the physiognomic class.
Hydrologic Class = Hydrologic class as defined in TNC's Terrestrial Vegetation Classification System. List of entries and descriptions provided in table (tbl_hydro_list_gap). Clicking the down arrow displays a brief description of the hydrological class.
Landform = Type of landform found at site. Some sites have more than one landform entry. The landforms are described in the table (tbl_landform_list_gap) or form (frm_landformdata). Clicking the down arrow displays a brief description along with other data about the landform.
Elevation = Elevation of the site represented in meters.
Aspect = Dominant aspect of the slope. Entry is restricted to an 8-class aspect list and N/A for slopes less than 3 degrees (For Example: SW, NE, S, etc.).
Slope = The estimated slope of the site area. Slope was divided into seven classes described in table (tbl_slope_az) were numeric minimum and maximum values derived from field data are recorded. Not all sites had slope estimates.
Tree Species = Acronym for tree species. (For Example: ABCO = Abies concolor).
cover % = The estimated canopy cover range for each each dominant species.
Shrub Species = Acronym for shrub species. (For Example: AMDU2=Ambrosia dumosa).
cover % = The estimated canopy cover range for each each dominant species.
Forb Species = Acronym for forb species. (For Example: ASLA4=Asclepias latifolia )
cover % = The estimated canopy cover range for each each dominant species.
Grass Species = Acronym for grass species. (For example: BRTE=Bromus tectorum).
cover % = The estimated canopy cover range for each each dominant species.
Site Comments = Additional comments about vegetation, disturbance, or other explanatory features at the training site.
The following includes a list of data field and its definition as seen on the Site Cover Data Form (For Example: frm_cover_data) in the MicroSoft Access Database:
% Cover = The estimated cover for vegetation and abiotic cover types.
% Trees = The estimated cover for all tree species at a site. (calculated)
% Shrubs = The estimated cover for all shrub species at a site. (calculated)
% Forbs = The estimated cover for all forbs species at a site. (calculated)
% Grasses = The estimated cover for all grass species at a site. (calculated)
% Total Plant = The estimated cover for all plant species at a site. (calculated)
% Bare Ground = The estimated cover for bare soil at a site.
% Litter = The estimated cover for litter at a site.
% Cryptobiotic Crust = The estimated cover for cryptobiotic crust at a site.
% Water = The estimated cover for water at a site.
% Surface Rock = The estimated cover for surface rock fragments at a site.
% Rock Outcrop = The estimated cover for exposed intact bedrock at a site.
% Total Land Cover = Summation of total percent cover of all land cover components (total vegetation + bare ground + litter + cryptobiotic crust + rock outcrop + surface rock + water) (Calculated field). Total coverage should not exceed 100%.
The following includes a list of data field and its definition as seen on the Adjusted UTM Data Form (For Example: frm_adjusted) in the MicroSoft Access Database:
Arizona field data were collected using GPS and the majority of samples were collected by traversing navigable roads. Survey data were collected for vegetation communities adjacent to roads. GPS coordinates for a portion of sample plots lie directly on the road, though the vegetation being described is adjacent to the road. Because this may present problems when using these data for remote sensing based applications, an adjusted UTM coordinate is provided for a number of the sample plots. These are available by clicking on the Globe button located under the 'Adjusted UTM'. GPS coordinates were not adjusted for all sample plots. Within the Adjusted UTM sub-form is a field that identified whether or not an adjusted coordinate is available. Coordinates were adjusted by visually inspecting every GPS coordinate with Landsat ETM imagery as a backdrop, and the appropriately recorded buffer distance displayed. The analyst made one of three choices: 1) determined the GPS coordinate was not on the road and was âokayâ, 2) determine the GPS coordinate was directly on the road, but could be moved with reasonable confidence to one or the other sides of the road, based on imagery in the backdrop (âyesâ) or 3) determined the GPS coordinate was directly on the road, but could not determine with reasonable confidence to which side of the road the sample location should be moved (ânoâ).
Adjusted = Yes/no/okay question if field UTM coordinates needed adjusted.
Easting (adj) = adjusted UTM easting coordinate (6 digits).
Northing (adj) = adjusted UTM northing coordinate (7 digits).
The following includes a list of data field and its definition as seen on the Range Cover Data Form (For Example: frm_cover_data_az) in the MicroSoft Access Database:
Range % Cover = The estimated cover range for vegetation and abiotic cover types.
R% Trees = The estimated cover range for all tree species at a site.
R% Shrubs = The estimated cover range for all shrub species at a site.
R% Forbs = The estimated cover range for all forbs species at a site.
R% Grasses = The estimated cover range for all grass species at a site.
R% Total Plant = The estimated cover range for all plant species at a site.
R% Bare Ground = The estimated cover range for bare soil at a site.
R% Litter = The estimated cover range for litter at a site.
R% Cryptobiotic Crust = The estimated cover range for cryptobiotic crust at a site.
R% Water = The estimated cover range for water at a site.
R% Surf Rock = The estimated cover range for surface rock fragments at a site.
R% Rock Outcrop = The estimated cover range for exposed intact bedrock at a site.
Ground Albedo = A 3-digit code corresponding to both the color and value of the ground.
Rock Outcrop Albedo = A 3-digit code corresponding to both the color and value of the exposed bedrock.
Total Site % Cover = Summation of total percent cover of all land cover components (total vegetation + bare ground + litter + cryptobiotic crust + rock outcrop + surface rock + water) (Calculated field). Total coverage should not exceed 100%.
The following includes a list of data field and its definition as seen on the Landform Data Form (For Example: frm_landformdata) in the MicroSoft Access Database:
Landform = descriptive term chosen from NRCS land form list (consistent with GAP "homogenous" plot).
Slope Range = normal limits of slopes (degrees) consistent with landform term.
Definition = simple description based on terms found in the dictionary of geologic terms.
Landscape Setting = three categories for coarse landscape description. Values include erosional, depositional, or mixed.
TNC Name = cross-walk for TNC/ABI reference. Not all landforms have a TNC Name assigned.
Best Fit Model = crosswalk to best theoritical matches with 10 class landform model. Not all landforms have a Best Fit Model assigned.
The following includes a list of data field and its definition as seen on the Plant Species Data Form (For Example: frm_plantdata) in the MicroSoft Access Database:
Plant Species = Acronym of plant species. Code from http:\\plants.usda.gov. Accessed March 2005.
Scientific Name = Scientific Name (Genus and Species).
Common Name = Common Name of plant species.
Family = Family of plant species.
The attribute values for the Ecological System were derived from: NatureServe. 2004. Landcover Descriptions for the Southwest Regional GAP Analysis Project.
The attribute values for tree, shrub, forb, and grass species were derived from: the Natural Resources Conservation Service (NRCS) On-Line Plants Database [<http://plants.usda.gov/>] current as of April 2005.