City of Portland Vegetation - ArcSDE version
1 IDENTIFICATION INFORMATION
1.1 Citation
Originator City of Portland
Publication date 20041216
Title City of Portland Vegetation
1.2 Description
Abstract Vegetation patches larger than 1/2 acre. Based on information from reference data sources including 6" resolution aerial photos, Parks and Recreation natural area assessments, and vegetation surveys along the banks of the Willamette and Columbia rivers. Vegetation patches area classified as forest, woodland, shrubland, or herbaceous. The mapping area includes all land within the City of Portland and the unincorporated parts of Multnomah County that are administered by the City of Portland.
Purpose For analyzing vegetation within Portland's riparian and upland areas. Developed as an input to the Bureau of Planning's GIS model for identifying significant natural resources.

The key goals of the vegetation mapping project were 1) refine the location of vegetation "patches" of areas previously mapped by Metro; 2) incorporate vegetation maps generated by other agencies such as Portland Parks and Recreation and the Portland Bureau of Environmental Services and refine and improve that information where necessary; 3) map vegetation patches meeting Portland’s criteria for inclusion in the natural resource inventory a 1/2 acre minimum patch size versus the 1 to 2 acre patch size used by Metro for the regional dataset; 4) map all vegetation within a 1/4 mile of a surface stream, wetland, or regionally significant habitat resources included in Metro’s inventory; 5) classify the vegetation into four NVCS classes: forest, woodland, shrubland, and herbaceous; 6) further classify vegetation as either "natural/semi-natural" or "cultivated"; and 7) update, refine and improve the vegetation data annually as new aerial photos become available.
Supplemental information Layer Files/Legends: vegetation_pdx.lyr
Vegetation patches are updated with each year's aerial imagery. For more information, refer to the Bureau of Planning vegetation mapping project documentation at:

http://www.portlandonline.com/shared/cfm/image.cfm?id=106047

This dataset is regularly updated.
1.3 Time period of content 20080324
Last Dataset Update Date 2013-09-01 22:19:25.0
1.4 Status
Progress In work
Maintenance/Update Frequency As needed
1.5 Spatial domain
Description Clackamas County, Multnomah County, and Washington County, Oregon
West bounding coordinate -123.15156069
East bounding coordinate -122.31651100
North bounding coordinate 45.70263875
South bounding coordinate 45.23396470
1.6 Keywords
Theme keyword thesaurus
Theme keyword vegetation, patches, landcover, classification
Place keyword thesaurus
Place keyword Portland, Multnomah County
1.7 Access Constraints For internal use only.
1.8 Use Constraints These data are distributed uner the terms of the City of Portland Data Distribution Policy.
1.10 Browse graphic
Browse graphic file name
Browse graphic file description
Browse graphic file type
1.13 Native data set environment Geodatabase
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2 DATA QUALITY INFORMATION
2.4 Horizontal positional accuracy

All vegetation polygons created or revised by the Bureau of Planning were manually digitized from aerial photos, with a horizontal accuracy of +/- 5' or better. Original Metro vegetation and river habitat surveys digitized from 2000 and 2002 aerial photos, also at +/- 5' or better. Original Parks and Recreation vegetation units digitized from aerials and June 2002 multispectral imagery, with a horizontal accuracy of approximately +/- 10'.
2.5 Lineage
Process step
Process description ORIGINAL DATA COMPILATION
All existing vegetation data was first combined into a single dataset. Original sources for vegetation were:

1) Parks and Recreation natural areas assessment - vegetation patches as digitized by Parks natural area assessment team using 2002 and 2003 aerial photographs. Patches were visited in the field by Parks technicians,  data about the patch was collected and recorded, and patch geometry and classes were changed as necessary based on the field data (avaialble online at http://www.parks.ci.portland.or.us/NaturalAreas/veg_survey/default.asp).

2) River habitat mapping - wildlife habitat areas along the Willamette and Columbia rivers. Habitat areas were defined as plant species and plant communities that support avian, mammalian, reptilian and amphibian species that use the riparian area. The boundaries of the original habitat area were mapped using 1998 and 1999 aerial photos and field visits. Original mapping done on contract with Adolfson and Associates, Inc. Habitat areas updated by the Bureau of Planning using 2000 and 2001 aerial photos.

3) Metro 2000 vegetation - a simple vegetation landcover layer collected via interpretation of Metro's 2000 digital orthophotographs. Polygons were digitized around forest, woody non-forest vegetation, open space, and developed gaps. Forest landcover types were delineated for the entire area within the Metro Service District and all sections within one mile beyond the District boundary. Woody non-forest vegetation and open space was delineated only within 300 feet of a mapped stream within the Metro Service District and all sections within one mile beyond the District boundary. Minimum mapping unit was 1 acre.
                                 
Process date 20040606
Process step
Process description MAPPING PROTOCOL
6" resolution aerial photos were the primary reference sources for identifying and revising vegetation patches. Vegetation patches are defined as an area of contiguous vegetation greater than 1/2 acre in size containing a distinct pattern, distribution, and composition of vegetation relative to surrounding vegetated and non-vegetated areas.

The specific mapping criteria were:
i. All vegetation patches visible on the aerial photos or classified as vegetation in a June 2002 multi-spectral image classification are reviewed for mapping.

ii. Vegetation is mapped as it appears on the aerials. Conflicts between the various reference data sources are resolved in the following order (with higher numbers receiving highest priority) (see Reference Data Sources section below for specific information on reference data sources):
 1. Metro’s regional vegetation map
 2. Willamette & Columbia River habitat maps
 3. Parks Bureau natural area assessment
 4. Aerial photos

iii. If the boundaries and class of a previously-mapped vegetation patch (Metro, Parks, etc.) are consistent with the aerials, then the patch is retained without modification. If a previously-mapped vegetation patch conflicts with the aerials, the geometry of the patch and/or the classification is modified to be consistent with the current aerial photos.

iv. Non-vegetated areas (buildings, bare soil, etc.) contained within a larger vegetation patch are removed if the non-vegetated area is greater than 1/2 acre in size. Areas of less than 1/2 acre are removed from the patch when the area is clearly visible (i.e., not partially or completely obscured by canopy.)

v. Patches are split when bisected by a 4-lane road or highway. Roads with less than 4 lanes split patches when they are clearly visible (i.e., there is no overhanging canopy) and the split will not result in patches of less than 1/2 acre.
                                 
                                 
                                 
Process date 20040606
Process step
Process description VEGETATION CLASSIFICATION (CLASS)
2002 through 2004 aerial photos were also the primary references for classifying vegetation patches into the four "National Vegetation Classification System" (NVCS) classes defined as follows:

1) Forest: Trees with their crowns overlapping (generally forming 60-100% of cover.)

2) Woodland: Open stands of trees with crowns not usually touching, generally forming 25-60% of cover. Tree cover may be less than 25% in cases where it exceeds shrubland and herbaceous vegetation.

3) Shrubland: Shrubs generally greater than 0.5 m tall with individuals or clumps overlapping to not touching, generally forming more than 25% of cover with trees generally less than 25% of cover. Shrub cover may be less than 25% where it exceeds forest, woodland, and herbaceous vegetation. Vegetation dominated by woody vines (i.e., blackberry) is generally included in this class.

4) Herbaceous: Herbs (graminoids, forbs, ferns and shrubs less than 0.5m tall) dominant, generally forming at least 25% of cover. Herbaceous cover may be less than 25% where it exceeds forest, woodland and shrubland vegetation. This includes shrubs less than 0.5 m tall.

Note that the 0.5 m height as a determination of class is difficult to apply consistently when using aerial photos as the primary reference source. It is often difficult to determine, without field verification, the exact height of shrubs and low-structure vegetation in a patch. Vegetation heights were therefore estimated by comparing the shadows cast with those of nearby features such as trees and houses. This is not possible in all areas. Therefore, the shrubland class tends to be applied to areas with larger, woody shrubs more easily visible on the current aerial photos.
                                 
                                 
Process date 20040607
Process step
Process description VEGETATION CLASSIFICATION (SUBGROUP)
Each vegetation patch was further classified into either “natural/semi-natural” or “cultivated” NVCS subgroups based on the following definitions :

1) Natural/Semi-Natural Vegetation: Natural vegetation is that which appears to be unmodified by human activities, occurring spontaneously without regular management, maintenance or planting. Semi-natural vegetation has a composition or structure that has been sufficiently altered by anthropogenic disturbances such that it no longer has the characteristics of natural vegetation assemblages found in comparable conditions the watershed. However, semi-natural vegetation is self-maintaining without significant human maintenance or management. This type of vegetation may be dominated by either native or non-native species.

2) Cultivated Vegetation: Vegetation that is consistent with traditional landscaping and is highly manicured and regularly (annually, semi-annually or more frequently) managed and maintained. Cultivated vegetation is often dominated by turf grasses and ornamental shrubs and trees. Cultivated vegetation typically has low species and structural diversity. It is assumed that cultivated areas are managed using a combination of mowing, pruning, fertilizers and pesticides. Residential yards, common areas, golf courses, parks and rights-of-way are included in this management class. In areas where agricultural land uses occur, cultivated fields and orchards are also included.

Most vegetation, particularly within an urban setting, has been subjected to human disturbance. Even where these impacts are apparent, if the patch appears to be self-sufficient and displays patterns consistent with uninhibited and un-maintained growth, the patch is identified as natural/semi-natural.

It is important to note that though natural/semi-natural areas may be dominated by native species, they need not be. An example of this would be a patch of Himalayan blackberry. Though these plants are not naturally-occurring in the Portland area, they are not generally planted or maintained and they distribute naturally, so they are mapped as an natual/semi-natural vegetation patch. The subgroup distinction is based on the pattern of plant distribution within the patch and the patch’s proximity to human features (such as houses and park infrastructure) rather than the type of vegetation present in the patch (which is often unknown).

Also note that forest vegetation is always designated as semi-natural/natural. This is appropriate because forested areas are dominated by trees which provide significant ecologic functions, such as rainwater capture, nutrient uptake, organic inputs, wildlife cover, etc. In addition, the forest canopy itself is not regularly maintained.                      
Process date 20040607
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3 SPATIAL DATA ORGANIZATION INFORMATION
3.2 Direct spatial reference method
3.3 Point and vector object information
SDTS point and vector object type Polygon
Point and vector object count 6037
3.4 Raster object information
Raster object type NA
Row count 0
Column count 0
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4 SPATIAL REFERENCE INFORMATION
4.1 Horizontal Coordinate System
Grid coordinate system name State plane coordinate system 1983(91).
SPCS zone identifier 5076
Planar distance units International feet
Horizontal datum name North American Datum of 1983/1991 (HPGN)
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5 ENTITY AND ATTRIBUTE INFORMATION
5.2 Overview description Related data files and field descriptions follow:
Table Name Column Name Column Type Column Width Sample Domain Value Definition
vegetation_pdx -- -- -- --
SOURCE String 50 -- The reference data source for the vegetation patch geometry and classification.
2003 Aerial Photos Patch was digitized using July 2003 6"/1’/2’ resolution aerial photos as reference.
2002 Multispectral Classification Patch was digitized using June 2002 multispectral image classification as reference. The classification identifies vegetation, bare soil, impervious surfaces, and water.
Parks Vegetation Assessment The existing 2003/2004 Parks natural area vegetation assessment patch was used without major modification.
River Habitat Maps The existing 2002 river habitat vegetation patch was used without major modification.
Metro 2000 Vegetation The existing Metro 2000 or 2002 update vegetation patch was used without major modification.
2004 Aerial Photos Patch was digitized using July 2004 6"/1’/2’ resolution aerial photos as reference.
2006 Aerial Photos Patch was digitized using July 2006 6"/1’/2’ resolution aerial photos as reference.
2005 Aerial Photos Patch was digitized using February or July 2005 6"/1’/2’ resolution aerial photos as reference.
NVCS_CLASS String 30 -- The vegetation patch "National Vegetation Classification System" (NVCS) class.
Forest Trees with their crowns overlapping, generally forming 60-100% of cover.
Woodland Open stands of trees with crowns not usually touching, generally forming 25-60% of cover. Tree cover may be less than 25% in cases where it exceeds shrubland and herbaceous vegetation.
Shrubland Shrubs generally greater than 0.5 m tall with individuals or clumps overlapping to not touching, generally forming more than 25% of cover with trees generally less than 25% of cover. Shrub cover may be less than 25% where it exceeds forest, woodland, and herbaceous vegetation. Vegetation dominated by woody vines (i.e., blackberry) is generally included in this class.
Herbaceous Herbs (graminoids, forbs, ferns and shrubs less than 0.5m tall) dominant, generally forming at least 25% of cover. Herbaceous cover may be less than 25% where it exceeds forest, woodland and shrubland vegetation. This includes shrubs less than 0.5 m tall.
PATCH_DESC String 50 -- The appended National Vegetation Classification System class and subgroup description. For example, a patch with a class of "Woodland" with a "Natural/Semi-natural" subgroup would have the patch description "Woodland Natural/Semi-natural."
NVCS_SUBCL String 150 -- The vegetation patch NVCS subclass, if known.
NVCS_GROUP String 200 -- The vegetation patch NVCS group, if known.
EDITOR String 30 -- The editor who created, modified, or classified the patch.
EDIT_DATE Date 36 -- The date of the last edit to the patch geometry or class.
REVIEW String 5 -- A yes/no (Y/N) tag indicating whether the patch needs further review. Further review consists of additional review by another editor and, if necessary, a field visit to the patch.
FLD_DATE Date 36 -- The date of any field visit to the patch.
ORIG_EDITO String 15 -- The original creator of the patch (if known).
OBJECTID Integer 4 -- A automatically-generated ID used by the GIS database.
NVCS_SUBGR String 50 -- The vegetation patch NVCS subgroup.
Natural/Semi-natural Natural vegetation is that which appears to be unmodified by human activities, occurring spontaneously without regular management, maintenance or planting. Semi-natural vegetation has a composition or structure that has been sufficiently altered by anthropogenic disturbances such that it no longer has the characteristics of natural vegetation assemblages found in comparable conditions the watershed. However, semi-natural vegetation is self-maintaining without significant human maintenance or management. This type of vegetation may be dominated by either native or non-native species.
Cultivated Vegetation that is consistent with traditional landscaping and is highly manicured and regularly (annually, semi-annually or more frequently) managed and maintained. Cultivated vegetation is often dominated by turf grasses and ornamental shrubs and trees. Cultivated vegetation typically has low species and structural diversity. It is assumed that cultivated areas are managed using a combination of mowing, pruning, fertilizers and pesticides. Residential yards, common areas, golf courses, parks and rights-of-way are included in this management class. In areas where agricultural land uses occur, cultivated fields and orchards are also included.
COMMENT Numeric 254 --
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6 DISTRIBUTION INFORMATION
6.1 Distributor
Contact organization City of Portland - BTS/CGIS
Address 1120 SW Fifth Avenue, Suite #450
City Portland
State or province OR
Postal code 97204
Contact voice telephone 503 823-5632
Contact facsimile telephone 503 823-9176
Contact electronic mail address CGIS@portlandoregon.gov
6.3 Distribution liability The information in this file was derived from digital databases on the City of Portland GIS. Care was taken in the creation of this file. The City  cannot accept any responsibility for errors, omissions, or positional accuracy.  There are no warranties, expressed or implied.
                                                       
6.4 Standard order process
Digital transfer information
Format name Shapefile - Cost Recovery fee will be charged for conversion.
Transfer size 14Mb
Digital transfer options:
Online option
Network resource name www.portlandonline.com
Access instructions The City of Portland can place the data on a CD upon request.  In most cases, a fee will be charged for data reproduction and preparation.  Call 503-823-5632 or e-mail cgis@ci.portland.or.us for instructions.
Offline option
Offline media CD-ROM
Recording format ISO9660 (DOS, Unix or Macintosh)
Fees
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7 METADATA REFERENCE INFORMATION
7.1 Metadata date 20130901
7.4 Metadata contact
Contact person Kevin Martin
Contact voice telephone 503 823-7710
Contact facsimile telephone 503 823-7800
Contact electronic mail address Kevin.Martin@portlandoregon.gov
7.5 Metadata standard name FGDC Content Standards for Digital Geospatial Metadata
7.6 Metadata standard version 19940608
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