This PNW Habitat Classification Systems database (PHaCS from this point forward) is a result of work done to fulfill task 4.4 of the Northwest Environmental Data-Network’s Scope of Work. The compilation of Habitat Classification Systems (Systems from this point forward) was accomplished by contacting 95 individuals from various governmental and non-governmental agencies and organizations, in addition to extensive searches via the internet. A total of 64 Systems were reviewed for this project with citations for each included in PHaCS (please see System Details below). Of those, categories were listed (with definitions when available) for 41 Systems; cross-walks to Habitat Type were completed for 27 of those Systems; cross-walks to Structural Conditions were completed for 10 of those Systems; and cross-walks to Key Environmental Correlates were completed for 30 of those Systems.
Semantic differences existed from the beginning, and at the very least, provided challenge for this project. Questions and different interpretations surround the term habitat; this has been previously recognized by Hall et al. (1997), and became evident when acquiring Systems for this project. Various interpretations of exactly what is a Habitat Classification System also exist, probably rooted in the fuzzy understanding of the term habitat.
Subsequently, the Systems compiled in PHaCS vary in detail, organization, and content. Individual classification groups, habitat elements, biological indicators, geomorphic classes, etc. are described as System categories in PHaCS.
Terrestrial and Aquatic Systems became the primary focus for acquisition for two reasons:
- A previous effort provided cross-walks between several Wetland Systems.
- Marine Systems were difficult to track down aside from NOAA’s efforts. However, Wetland and Marine systems were included when found.
Further,
PNW states took precedence for cross-walking; California Systems were included in
PHaCS, but were not cross-walked due to time constraints.
Cross-walks were established between System categories and the Interactive habitat and Biodiversity Information System (IBIS), developed by the Northwest Habitat Institute. The IBIS System was used because it provides detailed descriptions of three category levels (Habitat Types, Structural Conditions, and Key Environmental Correlates), and applies to terrestrial, aquatic, wetland, and marine environments. To accomplish the cross-walking effort, System categories were matched as closely as possible to the appropriate IBIS category by reading each category definition and matching parameters when possible.
A confidence level was also associated with each cross-walk. If category definitions existed, the cross-walk was usually straight-forward and therefore received a confidence level of high. A confidence level of medium was tagged to those cross-walks where the category did not have a definition, yet the category name made it possible to interpret a likely cross-walk. Some categories were more obscure, either in name or definition, and therefore cross-walks were merely suggestions; these cases were given a confidence level of low. If confidence levels do not exactly follow this process, comments were included.
The challenges associated with cross-walking include:
- differences between System organization
- differences in System detail
- differences in the format found for each system
- the sheer number of categories collected (over 5,300)
For example, Terrestrial Systems may use a physiognomic or a floristic approach to characterize habitats—and they may or may not include structural characteristics. Because IBIS uses a physiognomic approach, cross-walking to floristic Systems required the compilation of a spreadsheet listing all dominant and sub-dominant plant species found in each IBIS Habitat (as described in Johnson & O’Neil, 2001). Each floristic-based (e.g. plant-association-based) Terrestrial System category was then matched to an IBIS Habitat by searching the compiled dominant and sub-dominant plant species lists. This was incredibly time-consuming and resulted in the cross-walking of only a portion of the USDA Forest-Service Ecoclasses (over 2,000 total). Furthermore, some Systems were associated with maps using a GIS (mostly the EPA Ecoregion Systems). For these systems, if a map of IBIS Habitats also existed for a given geographic area, the cross-walking was accomplished by importing both maps into ArcMap and tabulating areas occupied by pixels of a particular IBIS Habitat. If the IBIS Habitat was occupied by >10% of a habitat from the other System, a cross-walk was recorded. Few Systems allowed this technique.
Future work might include gathering and cross-walking additional Systems which could be added to PHaCS. Because Systems vary in organization and detail, it may be useful to include any GIS mapping efforts using each system so that cross-walking could be done not only with definitions but also spatially, by map units. With refinement, a tool such as this could improve communication between agencies/organizations using different Systems, as implementing a “One System Fits All” approach may not prove practical.
Literature Cited
Hall, L. S., P. R. Krausman, and M. L. Morrison. 1997. The habitat concept and a plea for standard terminology. Wildlife Society Bulletin, 25(1): 173-182.
Johnson, D.H., and T.A. O’Neil. 2001. Wildlife-habitat relationships in Oregon and Washington. Oregon State University Press, Corvallis, Oregon.
PHaCS Content
The content of the
Pacific Northwest (PNW) Habitat Classification Systems database (PHaCS) includes the following areas:
Click on the titles below to view online:
Cross-walks
Cross-walking is a process of mapping elements from one standard or schema to another based on the definitions or semantics of these.
Cross-walks were established between Habitat Classification System (System) categories and the Interactive habitat and Biodiversity Information System (IBIS), developed by the Northwest Habitat Institute.
| User chooses System of interest from the drop-down menu, then generates a report with these cross-walks. Included in each report are the following: the System category name, any IBIS Habitats that relate to the category (in some cases there may be more than one), the IBIS Habitat Code (this can be referenced back to the IBIS Habitat Types list found on Page 2), the Confidence associated with the cross-walk (high, medium, or low—these are defined above), and any Comments associated with the cross-walk. |
| User chooses System of interest from the drop-down menu, then generates a report with these cross-walks. Included in each report are the following: the System category name, any IBIS SCs that relate to the category (in some cases there may be more than one), the IBIS SC Code (this can be referenced back to the IBIS SC list found on Page 2), the Confidence associated with the cross-walk (high, medium, or low—these are defined above), and any Comments associated with the cross-walk. |
User chooses System of interest from the drop-down menu, then generates a report with these cross-walks. Included in each report are the following:  | System category name | | Any IBIS KECs that relate to the category (in some cases there may be more than one) | | IBIS KEC Code (this can be referenced back to the IBIS KEC list found on Page 2) | | Confidence associated with the cross-walk (high, medium, or low—these are defined above) | | Any Comments associated with the cross-walk | |
| click title below to view online |
| User chooses IBIS Habitat from the drop-down menu, then generates a report with these cross-walks. Included in each report are the following: the System name, the System category name, the Confidence associated with the cross-walk (high, medium, or low—these are defined above), and any Comments associated with the cross-walk. |
| User chooses IBIS SC from the drop-down menu, then generates a report with these cross-walks. Included in each report are the following: the System name, the System category name, the Confidence associated with the cross-walk (high, medium, or low—these are defined above), and any Comments associated with the cross-walk. |
| User chooses IBIS KEC from the drop-down menu, then generates a report with these cross-walks. Included in each report are the following: the System name, the System category name, the Confidence associated with the cross-walk (high, medium, or low—these are defined above), and any Comments associated with the cross-walk. |
