National Wetland Plant List

AGENCY:

Army Corps of Engineers, DoD.

ACTION:

Notice.

SUMMARY:

The U.S. Army Corps of Engineers (USACE), as part of an interagency effort with the U.S. Environmental Protection Agency (EPA), the U.S. Fish and Wildlife Service (FWS) and the U.S. Department of Agriculture Natural Resources Conservation Service (NRCS), is announcing the availability of the final 2020 National Wetland Plant List (NWPL). The NWPL provides plant species indicator status ratings, which are used in determining whether the hydrophytic vegetation factor is met when conducting wetland delineations under the Clean Water Act and wetland determinations under the Wetland Conservation Provisions of the Food Security Act. Other applications of the NWPL include wetland restoration, establishment, and enhancement projects.

DATES:

The 2020 NWPL will become applicable on November 2, 2021, and will be used in any wetland delineations performed after this date. Delineations completed prior to this date may still use the 2018 NWPL. Completed wetland delineation/determination forms should reference the version of the NWPL used to complete the form.

ADDRESSES:

U.S. Army Corps of Engineers, Attn: CECW-CO-R, 441 G Street NW, Washington, DC 20314-1000.

FOR FURTHER INFORMATION CONTACT:

Brianne McGuffie, Headquarters, U.S. Army Corps of Engineers, Operations and Regulatory Community of Practice, Washington, DC 20314-1000, by phone at 202-761-4750 or by email at brianne.e.mcguffie@usace.army.mil.

SUPPLEMENTARY INFORMATION:

Background

The U.S. Army Corps of Engineers (USACE) administers the National Wetland Plant List (NWPL) for the United States (U.S.) and its territories. Responsibility for the NWPL was transferred to USACE from the U.S. Fish and Wildlife Service (FWS) in 2006. The NWPL has undergone several revisions since its inception in 1988. Additions or deletions to the NWPL represent new records, range extensions, nomenclatural and taxonomic changes, and newly proposed species. The latest review process began in 2020 and included review by Regional Panels (RPs), the National Panel (NP), and the public, who provided input on proposed wetland rating changes or additions for 27 species and 48 regional ratings (some species were reviewed for multiple regions) submitted by the public. Twenty of these species were proposed for addition to the NWPL, and seven species were submitted for a rating change request in one or more regions. The proposed indicator changes were announced in a Federal Register Notice, 86 FR 15656, March 24, 2021, with the comment period ending on May 24, 2021. Thirteen comments were received during that time.

Wetland Indicator Status Ratings

On the NWPL, there are five categories of wetland indicator status ratings, used to indicate a plant's likelihood for occurrence in wetlands versus non-wetlands: Obligate Wetland (OBL), Facultative Wetland (FACW), Facultative (FAC), Facultative Upland (FACU), and Upland (UPL). These rating categories are defined by the NP as follows: OBL—almost always occur in wetlands; FACW—usually occur in wetlands, but may occur in non-wetlands; FAC—occur in wetlands and non-wetlands; FACU—usually occur in non-wetlands, but may occur in wetlands; UPL—almost always occur in non-wetlands. These category definitions are qualitative descriptions that better reflect the qualitative supporting information, rather than numeric frequency ranges. The percentage frequency categories used in the older definitions are only used for testing problematic or contested species being recommended for indicator status changes. Plus and minus designations and wetland indicator designations such as No Indicator (NI), No Occurrence (NO), and No Agreement (NA) were removed in 2012 and are no longer used on the NWPL. More information on the specifics of how to use these ratings is available on the NWPL website at https://wetland-plants.sec.usace.army.mil/ .

The NWPL is utilized in conducting wetland delineations under the authority of Section 404 of the Clean Water Act (33 U.S.C. 1344) and Section 10 of the Rivers and Harbors Act of 1899 (33 U.S.C. 401 et seq. ) and wetland determinations under the authority of the Food Security Act of 1985 (16 U.S.C. 3801 et seq. ). For the purposes of determining how often a species occurs in wetlands, wetlands are defined as either (1) those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions (33 CFR 328.3) or (2) “except when such term is part of the term `converted wetland,' means land that has a predominance of hydric soils; is inundated or saturated by surface or groundwater at a frequency and duration sufficient to support a prevalence of hydrophytic vegetation typically adapted for life in saturated soil conditions; and under normal circumstances does support a prevalence of such vegetation.” (16 U.S.C. 3801(a)(27) and 7 CFR 12.2). Wetlands are identified using the three-factor approach. Because each species being evaluated occurs as part of a vegetation assemblage, examining the other species present in relation to their assigned wetland fidelity may be useful in assessing hydrophytic vegetation.

Discussion of Public Comments

For the 2020 NWPL update, the NWPL NP and RPs reviewed proposed wetland rating changes or additions for 27 species and 48 regional ratings (some species were reviewed for multiple regions) submitted by the public. Twenty of these species were proposed for addition to the NWPL, and seven species were submitted for a rating change request in one or more regions. Submitted information was reviewed by the NP and RPs, and proposed 2020 ratings for these species were determined. Along with soliciting information on the species being evaluated, we also solicited comments on the overall NWPL process. This information was detailed in the Federal Register Notice, 86 FR 15656, March 24, 2021 and is provided in the table below.

At the close of the comment period associated with the Federal Register notice, it was discovered that Spiranthes diluvialis, which was proposed for listing on the NWPL, was already included on the existing NWPL with the indicator status rating of FACW in the Arid West (AW), Great Plains (GP), and Western Mountains, Valleys, and Coast (WMVC). As a result, no action was taken with regard to Spiranthes diluvialis and the indicator status remains unchanged.

In response to the initial Federal Register notice, thirteen comments were received, addressing seven different species. One comment was regarding “ Populus fremontii” (synonym of Populus deltoides on the 2018 NWPL), recommending that the indicator status in the AW be changed from FAC to FACW. However, this species was not proposed for review or recommended indicator status change at the beginning of the 2020 update process and is therefore not included in this update effort. The proposed change to this species will be evaluated in the 2022 NWPL update. Another comment was on Echinacea laevigata in the Atlantic and Gulf Coastal Plain (AGCP) and the Eastern Mountains and Piedmont (EMP). The commenter agreed with the proposed indicator status of FACU for both regions. The main point of this comment was questioning whether rare species, such as E. laevigata, should be included on the NWPL. This comment was reviewed by the NWPL RPs and NP and there was overall agreement that it is appropriate to include all species for which we have adequate data to support assignment of an indicator status.

One commenter recommended that Boltonia decurrens in the Midwest (MW) be rated FACW, rather than the proposed FAC. Five commenters recommended that Populus balsamifera in the WMVC be rated FAC, rather than the proposed FACW. Three commenters, two in the AW and one in the WMVC, recommended that Vinca major be rated FACU, rather than the proposed FAC. These recommendations were reviewed by the NWPL RPs and NP, along with literature, specimen collection data, and professional experience and the commenters' recommendations were chosen as the final ratings for each of these three species.

One commenter recommended that Platanthera praeclara in the MW be rated FACW, rather than the proposed FAC. This recommendation was reviewed by the MW and GP RPs and the NP, along with literature, specimen collection data, and professional experience and the commenter's recommendation of FACW was chosen as the final rating in both the MW and the GP.

One commenter recommended that Hypericum calycinum in the AW be rated UPL, rather than the proposed FAC. This recommendation was reviewed by the AW and WMVC RPs and the NP, along with literature, specimen collection data, and professional experience. Based on this review, FACU was assigned as the indicator status for Hypericum calycinum in both the AW and WMVC Regions.

As part of the 2020 NWPL update, USACE also proposed making two administrative changes with the Hawai'i and Pacific Islands Region (HI) and the South Pacific Islands Subregion (SPI). No comments were received from the public on this proposal. NWPL subregions are areas in which small numbers of wetland plants have wetland indicator status ratings that differ from the ratings for the same plant species in the rest of the region. Boundaries of subregions are typically based on Major Land Resource Areas. Under the previous format, the SPI included certain plant species which had an indicator status rating for SPI but not for HI (see e.g., indicator status ratings for Abildgaardia ovata; SPI= FACW, HI= NL). This previous format of HI/SPI is inconsistent with the formatting of other NWPL regions and subregions and has caused some confusion when applying the NWPL within HI.

To address this confusion, USACE finalized the two proposed administrative changes, neither of which affect the current boundaries of SPI, HI, or any other NWPL regions or subregions. First, USACE reformatted SPI and HI by merging the lists of plant species from the existing SPI and HI to form a single, comprehensive region, with SPI serving as a subregion of HI, instead of the previous state of the region in which SPI served as a stand-alone subregion separate from the larger HI region. Plant species that had an indicator status rating for SPI but not for HI ( e.g., Abildgaardia ovata ) now have a single, comprehensive indicator status rating for the entire region (HI). For those species which had differing indicator status ratings between SPI and HI ( e.g., Abrus precatorius ), the indicator status rating for SPI has been added to the reformatted SPI, which will serve as a subset of indicator status ratings within HI, and includes only those plant species and associated indicator status ratings which differ from the HI indicator status rating. With the exception of Xylocarpus moluccensis and Ligustrum lucidum, which were recommended changes submitted by the public, all indicator status ratings for SPI and HI were retained through this reformatting. This administrative change provides greater clarity for the public, removes redundancies in the NWPL that existed between SPI and HI, allows for a consistent formatting of subregions between all NWPL regions, and more accurately and appropriately reflects species' distribution and wetland frequency within SPI and HI.

In addition to reformatting SPI and HI to form a single, comprehensive region, USACE also renamed SPI from its current name, “South Pacific Islands Subregion”, to “Pacific Islands Subregion.” This subregion includes islands which are located within both the northern Pacific ( i.e., the Commonwealth of the Northern Mariana Islands and the Territory of Guam) and southern Pacific ( i.e., the Territory of American Samoa). Therefore, the name change more accurately characterizes the geographic extent and spatial variability of this subregion. This change also creates consistency between the naming conventions of the NWPL regions and subregions and the Regional Supplements to the Corps of Engineers Wetland Delineation Manual regions.

In accordance with the Memorandum of Agreement signed in 2017 (2017 MOA), future updates to the NWPL will continue to occur biennially. The public may provide input to be considered as part of future NWPL updates by utilizing the following procedures. A change in indicator status or addition of a currently unlisted species may be requested at any time at https://wetland-plants.sec.usace.army.mil/ by clicking on the “Submit a NWPL Change Request” link and submitting the appropriate data. Appropriate data includes ecological data, literature reviews, frequency and abundance data, testing descriptions, and geographic data for the taxon in wetlands and non-wetlands in the USACE wetland region or subregion for which the change is proposed.

In accordance with the Memorandum of Agreement signed in 2006 (2006 MOA), USACE, endorsed by the EPA, FWS and NRCS, is publishing final wetland indicator statuses for the 2020 NWPL. The final NWPL is available at https://wetland-plants.sec.usace.army.mil/. State, regional, and national lists can also be downloaded from this site. This completes the review of the NWPL. All comments received have been evaluated and final indicator statuses have been set.

Detailed information on the update process, protocol, and technical issues can be found in the following documents (available on the NWPL Publications web page):

• Lichvar, Robert W. and Minkin, Paul. Concepts and Procedures for Updating the National Wetland Plant List. Sept 2008. ERDC/CRREL TN-08-3. Hanover, NH: U.S. Army Engineer Research and Development Center, Cold Regions Research and Engineering Laboratory.
• Lichvar, Robert W. and Gillrich, Jennifer J. Final Protocol for Assigning Wetland Indicator Status Ratings during National Wetland Plant List Update. Sept 2011. ERDC/CRREL TN-11-1. Hanover, NH: U.S. Army Engineer Research and Development Center, Cold Regions Research and Engineering Laboratory.

Additional cited literature:

Lichvar R.W., N.C. Melvin, M.L. Butterwick, and W.N. Kirchner. 2012. National Wetland Plant List Indicator Rating Definitions. ERDC/CRREL TN-12-1. Hanover, NH: U.S. Army Engineer Research and Development Center Cold Regions Research and Engineering Laboratory

Environmental Documentation

A decision document has been prepared for this action after all comments received were evaluated. The decision document is available through Headquarters, U.S. Army Corps of Engineers, Operations and Regulatory Community of Practice, 441 G Street NW, Washington, DC 20314-1000.

Authority

The NWPL is utilized in conducting wetland determinations under the authority of the Food Security Act of 1985 (16 U.S.C. 3801 et seq. ) and wetland delineations under the authority of Section 404 of the Clean Water Act (33 U.S.C. 1344) and Section 10 of the Rivers and Harbors Act of 1899 (33 U.S.C. 401 et seq. ). The Corps has responsibility for issuing this update pursuant to the 2006 MOA.