An Overview of the National Vegetation Classification Standard
and its Application in the Fish and Wildlife Service

The overall objective of the National Vegetation Classification Standard (NVCS) is to support the use of a consistent national vegetation classification to produce uniform statistics in vegetation resources from vegetation cover data at the national level. Adoption of the NVCS and subsequent development and application of vegetation mapping schemes will facilitate the compilation of regional and national summaries. In turn, the consistent collection of such information will eventually support the detailed, quantitative, georeferenced basis for vegetation cover modeling, mapping, and analysis at the field level.

The standard presented represents more the minimum required than the ideal or maximum. The purpose of the national standard is to require all federal vegetation classification efforts to have some core components that are the same across all federal agencies. This will permit aggregating data from all federal agencies. These standards are intended to be used by federal agencies and as needed by other groups including those engaged in land use planning or management by county and state governments, teaching or research uses, and by the private sector. The adopted standards must be followed by all Federal agencies for data collected directly or indirectly (through grants, partnerships, or contracts). Currently the policy for applying the standard is only through the formation level.

The NVCS provides a standard framework and classification approach for natural, semi-natural, planted and cultivated vegetation types. All areas having equal to or more than 1% of the surface area with live vegetation cover are classified within the NVCS. The vegetation classification standard is hierarchical and combines floristics at the lowest levels and physiognomy and broad ecological modifiers at the highest levels of the hierarchy. This approach allows the characterization of vegetation patterns at multiple spatial scales. Cultivated and managed vegetation types are included in this classification standard due to their extensive geographical coverage and the importance of identifying, mapping, and monitoring these types. In addition to vegetation found on strictly upland environments, this classification includes wetland vegetation (rooted emergent and floating).

The standards do not dictate values for several mapping-related parameters such as minimum mapping unit, polygon minimum width thresholds, etc.. Rather, the NVCS should be employed using the most appropriate level(s) in the hierarchy, in concert with application-specific mapping protocols which provide for the retention of appropriate information.

For a complete copy of the standard visit the FGDC Vegetation Subcommittee homepage at http://biology.usgs.gov/fgdc.veg/ on the WWW.

The hierarchy for the NVCS is presented below.

National Vegetation Classification Standard

Applying the National Vegetation Classification Standard requires two separate but interrelated activities:

1) data collection and management for vegetation classification and reporting at different levels of the hierarchy (field data collection and verification)
2) management and reporting of vegetation information associated with vegetation maps. (actual mapping program)

This standard has undergone extensive national review and was adopted as a national standard on October 22, 1997 by the FGDC. What that will mean for the Fish and Wildlife Service is yet to be determined. Several potential options are outlined below. A national workgroup has been formed to deal with this issue, under the guidance of Nancy Roeper, Refuges and Wildlife, R9. The benefits to the Service as well as the costs ( time and dollars) need to be described. The National Conservation Training Center (NCTC) will also be involved as they are offer a class on vegetation classification that can assist in implementation of the standard.

DRAFT FWS Implementation Options:

1- Complete implementation of the standard, including full verification of the classification with field plots as is being done in the Park Service. Scientifically this would yield the most accurate information and give field managers very detailed data. Practically, this option is very expensive both in time and dollars. The Park Service received special funding to begin this process, which the Fish and Wildlife Service does not have. It would require either extensive training of field staff in plant taxonomy or contracts with outside sources. If all vegetation maps were created in this manner, it would take many years to complete.

2- Adoption of the standard for as a classification for maps, but with minimal field verification. This option could use traditional photo interpretation techniques, substituting the national classification system for the multitude of systems now in use. Field verification would occur in conjunction with other field work. Verification could be more intense in areas where special resource indicate the need for more scientific data.

3- Generally adopt the standard as a mapping classification, but select at least one refuge in each region or ecosystem to see what application of the full field verification involves. This has already been done for Chincoteague NWR in Virginia, but application considerations may vary considerably in other ecosystems or in areas where the classification is either more or less developed.

Comments? Suggestions?

For additional information regarding this Web page, contact Deb Southworth Green, in the Division of Information Resources and Technology Management, at Deb_Green@fws.gov

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Keywords=GIS, data, metadata, steering, veg, vegetation
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